document_title: History of the Ottoman Empire during World War I

question_text: when did the ottoman empire surrender in ww1

text: Military activities[edit]

text: The Ottoman entry into World War I began on 29 October 1914 when it launched the Black Sea Raid against Russian ports. Following the attack, Russia and its allies (Britain and France) declared war on the Ottomans in November 1914. The Ottoman Empire started military action came after three months of formal neutrality, but it had signed a secret alliance with the Central Powers in August 1914.

text: The political reasons for the Ottoman Sultan's entry into the war are disputed.[1] and the Ottoman Empire was an agricultural state in an age of industrialized warfare,[2] Also, the economic resources of the empire were depleted by the cost of the Balkan Wars of 1912 and 1913.

text: The great land mass of Anatolia was between the Ottoman army's headquarters in Istanbul and many of the theatres of war. During Abdulhamit II's reign civilian communications had improved, but the road and rail network was not ready for war.[2] It took more than a month to reach Syria and nearly two months to reach Mesopotamia. To reach the border with Russia, the railway ran only 60 km east of Ankara, and from there, it was 35 days to Erzurum.[2] The Army used Trabzon port as logistical shortcut to east. It took less time to arrive at any of those fronts from London than from the Ottoman War Department because of the poor condition of Ottoman supply ships.

text: The empire fell into disorder with the declaration of war along with Germany. On 11 November a conspiracy was discovered in Constantinople against Germans and the Committee of Union and Progress (CUP) in which some of the CUP leaders were shot. That followed the 12 November revolt in Adrianople against the German military mission. On 13 November, a bomb exploded in Enver Pasha's palace, which killed five German officers but missed the Enver Pasha. On 18 November were more anti-German plots. Committees formed around the country to rid the country of those who sided with Germany. Army and navy officers protested against the assumption of authority by Germans. On 4 December, widespread riots took place throughout the country. On 13 December was an anti-war demonstration by women in Konak (Izmir) and Erzurum. Throughout December, the CUP dealt with mutiny among soldiers in barracks and among naval crews. The head of the German Military Mission, Field Marshal von der Goltz, survived a conspiracy against his life.

text: The military power remained firmly in the hands of War Minister Enver Pasha, domestic issues (civil matters) on Interior Minister Talat Pasha, and, an interesting point, Cemal Pasha had sole control over Ottoman Syria.[3] Rest of the governance, provincial governors, ran their regions with differing degrees of autonomy.[3] An interesting case is Izmir; Rahmi Bey behaved almost as if his region was a neutral zone between the warring states.[4]

tag: table

text: War with Russia[edit]

text: Ottoman's entrance into the war greatly increased the Triple Entente's military burdens. Russia had to fight on the Caucasus Campaign alone and in the Persian Campaign along with the United Kingdom. İsmail Enver Pasha set off for the Battle of Sarikamish with the intention of recapturing Batum and Kars, overrunning Georgia and occupying north-western Persia and the oil fields. Fighting the Russians in the Caucasus, however, the Ottomans lost ground, and over 100,000 soldiers, in a series of battles. 60,000 Ottoman soldiers died in the winter of 1916—17 on the Mus—Bitlis section of the front.[5] Ottomans preferred to keep the Caucasus militarily silent as they had to regroup reserves to retake Baghdad and Palestine from the British. 1917 and first half of 1918 was the time for negotiations. On 5 December 1917, the armistice of Erzincan (Erzincan Cease-fire Agreement) signed between the Russians and Ottomans in Erzincan that ended the armed conflicts between Russia and Ottoman Empire.[6] On 3 March, the Grand vizier Talat Pasha signed the Treaty of Brest-Litovsk with the Russian SFSR. It stipulated that Bolshevik Russia cede Batum, Kars, and Ardahan. In addition to these provisions, a secret clause was inserted which obligated the Russians to demobilize Armenian national forces.[7]

text: Between 14 March – April 1918 the Trabzon peace conference held among the Ottoman Empire and the delegation of the Transcaucasian Diet. Enver Pasha offered to surrender all ambitions in the Caucasus in return for recognition of the Ottoman reacquisition of the east Anatolian provinces at Brest-Litovsk at the end of the negotiations.[8] On 5 April, the head of the Transcaucasian delegation Akaki Chkhenkeli accepted the Treaty of Brest-Litovsk as a basis for more negotiations and wired the governing bodies urging them to accept this position.[9] The mood prevailing in Tiflis was very different. Tiflis acknowledge the existence of a state of war between themselves and the Ottoman Empire.[9]

text: In April 1918, the Ottoman 3rd Army finally went on the offensive in Armenia. Opposition from Armenian forces led to the Battle of Sardarapat, the Battle of Kara Killisse (1918), and the Battle of Bash Abaran. On 28 May 1918, the Armenian National Council based in Tiflis declared the Democratic Republic of Armenia. The new Republic of Armenia was forced to sign the Treaty of Batum.

text: In July 1918, Ottomans faced with the Centrocaspian Dictatorship at the Battle of Baku, with the goal of taking Britain Baku on the Caspian Sea.

text: War with Britain[edit]

text: The British captured Basra in November 1914, and marched north into Iraq.[5] Initially Ahmed Djemal Pasha was ordered to gather an army in Palestine to threaten the Suez Canal. In response, the Allies—including the newly formed Australian and New Zealand Army Corps ("ANZACs")—opened another front with the Battle of Gallipoli. The army led by Ahmed Djemal Pasha (Fourth Army) to eject the British from Egypt was stopped at the Suez canal in February 1915, and again the next summer.[5] The canal was vital to the British war effort. The 1915 locust plague breaks out in the Palestine region, to be exact the Ottoman military hospitals record the period as March–October 1915:

text: The expected, and feared, British invasion came not through Cilicia or northern Syria, but through the straits.[3] The aim of the Dardanelles campaign was to support Russia. Most military observers recognized that the uneducated Ottoman soldier was lost without good leadership, and at Gallipoli Mustafa Kemal realized the capabilities of his man if their officers led from the front.[11] The war was something from a different era, as the agrarian Ottoman Empire faced two industrialized forces, at silent predawn attacks in which officers with drawn swords vent ahead of troops and only the troops to shout their battlecry of "Allahu Akbar!" when they reached the enemy’s trenches.[11]

text: The United Kingdom was obliged to defend India and the southern Persian oil territory by undertaking the Mesopotamian campaign. Britain also had to protect Egypt in the Sinai-Palestine-Syria Campaign. These campaigns strained Allied resources and relieved Germany.

text: The repulse of British forces in Palestine in the spring of 1917 was followed by the loss of Jerusalem in December of the same year.[5] The Ottoman authorities deport the entire civilian population of Jaffa and Tel Aviv, The Tel Aviv and Jaffa deportation, pursuant to the order from Ahmed Jamal Pasha on 6 April 1917. The Muslim evacuees allowed to return before long, At the same period the Balfour Declaration was being negotiated (published on 2 November 1917) in which the British Government declares its support for the establishment of a Jewish national home in Palestine. Ahmed Jamal Pasha effectively separates these groups. The Jewish evacuees returned after the British conquest of Palestine.[12]

text: The Ottomans were eventually defeated due to key attacks by the British general Edmund Allenby.

text: Empire in home front[edit]

text: The war tested to the limit the empire’s relations with its Arab population.[13] In February 1915 in Syria, Cemal Pasha exercised absolute power in both military and civil affairs.[14] Cemal Pasha was convinced that an uprising among local Arabs was imminent.[13] Leading Arabs were executed, and notable families deported to Anatolia.[13] Cemal’s policies did nothing to alleviate the famine that was gripping Syria; it was exacerbated by a British and French blockade of the coastal ports, the requisitioning of transports, profiteering and — strikingly — Cemal’s preference for spending scarce funds on public works and the restoration of historic monuments[13][15] During the war, Britain had been a major sponsor of Arab nationalist thought and ideology, primarily as a weapon to use against the power of the Empire. Sharif Hussein ibn Ali rebelled against the Ottoman rule during the Arab Revolt of 1916. In August he was replaced by Sharif Haydar, but in October he proclaimed himself king of Arabia and in December was recognized by the British as an independent ruler.[13] There was little the Empire could do to influence the course of events, other than try to prevent news of the uprising spreading, prevent it to demoralize the army or act as a propaganda for anti-Ottoman Arab factions.[13] On 3 October 1918 forces of the Arab Revolt enter Damascus accompanied by British troops, ending 400 years of Ottoman rule.

text: War in Eastern Europe[edit]

text: In order to support the other Central Powers, Enver Pasha sent 3 Army Corps or around 100.000 men to fight in Eastern Europe. [16]

text:
VI Corps under command of Mustafa Hilmi Pasha participated in the Romanian Campaign between September 1916 and April 1918.
XV Corps under command of Yakup Şevki Subaşı and later Cevat Pasha fought in Galicia against the Russians between August 1916 and August 1917.
XX Corps under command of Abdul Kerim Pasha participated in the Salonika Campaign between December 1916 and May 1917.

The Rumeli Field Detachment (reinforced 177th Infantry Regiment) remained in Macedonia until May 1918.

tag: ul

text: Political activities[edit]

text: The Constantinople Agreement on 18 March 1915 was a set of secret assurances, which Great Britain promised to give the Capital, and the Dardanelles to the Russians in the event of victory.[17] The city of Constantinople was intended to be a free port.

text: During 1915, British forces invalidated the Anglo-Ottoman Convention, declaring Kuwait to be an "independent sheikdom under British protectorate."[this quote needs a citation]

text: Capitulations and public debt, 1915[edit]

text: On 10 September 1915, Interior Minister Talat Pasha abolished the "Capitulations". On 10 September 1915 Grand Vizier Said Halim Pasha annulled (Vizer had the authority on annuls) the Capitulations, which ended the special privileges they granted to foreign nationals. The capitulation holders refused to recognize his action (unilateral action).[2] The American ambassador expressed the Great Power view:

text: The capitulary regime, as it exists in the Empire, is not an autonomous institution of the Empire, but the result of international treaties, of diplomatic agreements and of contractual acts of various sorts. The regime, consequently, cannot be modified in any of its parts and still less suppressed in its entirety by the Ottoman Government except in consequence of an understanding with the contracting Powers.[18]

text: Beside the capitulations, there was another issue which evolved under the shadow of capitulations. The dept and financial control (revenue generation) of the empire was intertwined under single institution, which its board was constituted from Great Powers rather than Ottomans. There is no sovereignty in this design. The public debt could and did interfere in state affairs because it controlled (collected) one-quarter of state revenues.[18] The debt was administered by the Ottoman Public Debt Administration and its power extended to the Imperial Ottoman Bank (equates to modern central banks). Debt Administration controlled many of the important revenues of the empire. The council had power over every financial affairs. Its control extended to determine the tax on livestock in districts. Ottoman public debt was part of a larger scheme of political control, through which the commercial interests of the world had sought to gain advantages that may not be to Empire's interest. The immediate purpose of the abolition of capitulations and the cancellation of foreign debt repayments was to reduce the foreign stranglehold on the Ottoman economy; a second purpose — and one to which great political weight was attached – was to extirpate non—Muslims from the economy by transferring assets to Muslim Turks and encouraging their participation with government contracts and subsidies.[19]

text: The French-Armenian Agreement of 27 October 1916, was reported to the interior minister, Talat Pasha, which agreement negotiations were performed with the leadership of Boghos Nubar the chairman of the Armenian National Assembly and one of the founder of the AGBU.

text: In 1917 the Ottoman Cabinet considered maintaining relations with Washington after the United States had declared war on Germany on 6 April. But the views of the war party prevailed and they insisted on maintaining a common front with their allies. Thus, relations with America were broken on 20 April 1917.

text: Diplomacy with new Russia, 1917[edit]

text: The 1917 Russian revolution changed the realities. The war devastated not only Russian soldiers, also the Russian economy was breaking down under the heightened strain of wartime demand by the end of 1915. The tsarist regime’s advances for the security on its southern borders proved ruinous.[20] The tsarist regime's desire to control the Eastern Anatolia and the straits (perceived as an underbelly), in the end created the conditions that brought about Russia's own downfall. Unable to use Straits disrupted the Russian supply chain. Russia might survived without the Straits, but the strain was the tipping point for its war economy.[20] This question was left to Soviet historians: "whether a less aggressive policy toward the Ottoman Empire before the war would have caused Istanbul to maintain neutrality or whether Russia later might have induced Istanbul to leave the war,[a] the outcome of tsarist future would be different.[20] Nicholas's inept handling of his country and the war destroyed the Tsar and ended up costing him both his reign and his life.

text: Enver immediately instructed the Vehib Pasha, Third Army, to propose a ceasefire to Russia’s Caucasus Army.[21] Vehib cautioned withdrawing forces, as due to the politics in Russia — neither Russia’s Caucasus Army nor Caucasian civil authorities give assurance that an armistice would hold.[22] On 7 November 1917 the Bolshevik Party led by Vladimir Lenin over threw the Provisional Government in a violent coup plunged Russia into multitude of civil wars between ethnic groups. The slow dissolution of Russia’s Caucasus Army relieved one form of military threat from the east but brought another one. Russia was a long time threat, but at the same time kept the civil unrest in his land at bay without spreading to Ottomans in a violent. On 3 December the Ottoman foreign minister Ahmed Nesimi Bey informed the "Chamber of Deputies" about the prospects. Chamber discussed the possible outcomes and priorities. On 15 December Armistice between Russia and the Central Powers signed. On 18 December Armistice of Erzincan signed. The Bolsheviks’ anti-imperialist formula of peace with no annexations and no indemnities was close to Ottoman position. The Bolsheviks' position brought a conflict with the Germany's aim to preserve control over the East European lands it occupied and with Bulgaria’s claims on Dobruja and parts of Serbia. In December Enver informed the Quadruple Alliance that they would like to see the 1877 border (Russo-Turkish War (1877–1878)), pointing out that the only Ottomans lost territory and 1877 boarder was Ottoman territories inhabited by Muslims.[23] Ottomans did not pushed 1877 position too hard, scared to fall back to bilateral agreements. On the other hand, Germany, Austria-Hungary, and Bulgaria clearly stood behind on the pulling back the Ottoman and Russian forces from Iran.[24] Ottomans wanted Muslim Iran be under its own control. The ambassador to Berlin, Ibrahim Hakki Pasha, wrote: "Although Russia may be in a weakened state today, it is always an awesome enemy and it is probable that in a short time it will recover its former might and power.[23]

text: On 22 December 1917, the first meeting between Ottomans and the Bolsheviks, the temporary head Zeki Pasha, until Talat Pasha's arrival, requested of Lev Kamenev to put an end to atrocities being committed on Russian-occupied territory by Armenian partisans. Kamenev agreed and added "an international commission should be established to oversee the return of refugees (by own consent) and deportees (by forced relocation) to Eastern Anatolia. The battle of ideals, rhetoric, and material for the fate of Eastern Anatolia opened with this dialog .[23]

text: The Treaty of Brest-Litovsk represented an enormous success for the empire.[according to whom?] Minister of Foreign Affairs Halil Bey announced the achievement of peace to the Chamber of Deputies. He cheered the deputies further with his prediction of the imminent signing of a third peace treaty (the first Ukraine, second Russia, and with Romania). Halil Bey thought the Entente to cease hostilities and bring a rapid end to the war. The creation of an independent Ukraine promised to cripple Russia, and the recovery of Kars, Ardahan and Batum gave the CUP a tangible prize. Nationalism emerged at the center of the diplomatic struggle between the Central Powers and the Bolsheviks. Empire recognized that Russia’s Muslims, their co-religionists, are disorganized and dispersed to come out as an entity in the future battles of ideals, rhetoric, and material. Thus, the Ottomans mobilized the Caucasus Committee to make claims on behalf of the Muslims.[25] The Caucasus Committee had declined Ottoman earnest requests to break from Russia and embrace independence. The Caucasian Christians was far ahead in this new world concept. Helping the Caucasian Muslims to be free, like their neighbors, would be the Ottomans’ challenge.[25]

text: In the overall war effort, the CUP was convinced that empire's contribution was essential. Ottoman armies had tied down large numbers of Allied troops on various fronts, keeping them away from theatres in Europe where they would have been used against German and Austrian forces. Moreover, they claimed that their success at Gallipoli had been an important factor in bringing about the collapse of Russia, resulting in the revolution of April 1917. They had turned the war in favor of Germany and her allies.[26] Hopes were initially high for the Ottomans that their losses in the Middle East might be compensated for by successes in the Caucasus Campaign. Enver Pasha maintained an optimistic stance, hid information that made the Ottoman position appear weak, and let most of the Ottoman elite believe that the war was still winnable.[27]

text: Diplomacy with new states, 1918[edit]

text: Ottoman policy toward the Caucasus evolved according to the changing demands of the diplomatic and geopolitical environment.[28] What was the Ottoman premise in involving with the Azerbaijan and the North Caucasus? The Empire’s leaders, in the parliament discussions throughout 1917, understood that Russia’s collapse presented a historic window of opportunity to redraw the map of the Caucasus. They were convinced, however, that soon enough Russia would recover and reemerge as the dominant power in the region and shut that window.

text: The principle of "self-determination" became the criterion, or at least in part, to give them a chance to stand on their feet.[29] The Bolsheviks did not regard national separatism in this region as a lasting force. Their expectation was whole region come under a "voluntary and honest union" [b] and this union bearing no resemblance to Lenin’s famous description of Russia as a "prison house of peoples."[30] Lenin's arrival to Russia was formally welcomed by Nikolay Chkheidze, the Menshevik Chairman of the Petrograd Soviet.

text: Ottoman's did not see a chance of these new states to stand against new Russia. These new Muslim states needed support to be emerged as viable independent states. In order to consolidate a buffer zone with Russia (both for the Empire and these new states), however, Ottomans needed to expel the Bolsheviks from Azerbaijan and the North Caucasus before the end of war.[31] Based on 1917 negotiations, Enver concluded that Empire should not to expect much military assistance from the Muslims of the Caucasus as they were the one in need. Enver also knew the importance of Kars—Julfa railroad and the adjacent areas for this support. Goal was set forward beginning from 1918 to end of the war.

text: The Empire duly recognized the Transcaucasian Democratic Federative Republic in February 1918. This preference to remain part of Russia led Caucasusian politics to the Trebizond Peace Conference to base their diplomacy on the incoherent assertion that they were an integral part of Russia but yet not bound[28] The representatives were Rauf Bey for the Empire, and Akaki Chkhenkeli from the Transcaucasian delegation.

text: On 11 May, a new peace conference opened at Batum. The Treaty of Batum was signed on 4 June 1918, in Batum between the Ottoman Empire and three Trans-Caucasus states: First Republic of Armenia, Azerbaijan Democratic Republic and Democratic Republic of Georgia.

text: The goal was to assist Azerbaijan Democratic Republic at Battle of Baku, then turn north to assist the embattled Mountainous Republic of the Northern Caucasus and then sweep southward to encircle the British in Mesopotamia and retake Baghdad.[29] The British in Mesopotamia already moving north, with forty vans (claimed to loaded with gold and silver for buying mercenary) accompanied with only a brigade, to establish a foothold. At the time Baku was under the control of the 26 Baku Commissars which were Bolshevik and Left Socialist Revolutionary (SR) members of the Baku Soviet Commune. The commune was established in the city of Baku. In this plan, they expected resistance from Bolshevik Russia and Britain, but also Germany, which opposed the extension of their influence into the Caucasus.[29] Ottoman's goal to side with Muslims of Azerbaijan and MRNC managed to get Bolsheviks of Russia, Britain and Germany on the same side of a conflict box at this brief point in the history.

text: Winding down toward the armistice, 1918[edit]

text: Developments in Southeast Europe squashed the Ottoman government's hopes. In September 1918, the Allied forces under the command of Louis Franchet d'Espèrey mounted a sudden offensive at the Macedonian Front, which proved quite successful. Bulgaria was forced to sue for peace in the Armistice of Salonica. This development undermined both the German and Ottoman cause simultaneously - the Germans had no troops to spare to defend Austria-Hungary from the newly formed vulnerability in Southeast Europe after the losses it had suffered in France, and the Ottomans suddenly faced having to defend Istanbul against an overland European siege without help from the Bulgarians.[27]

text: Grand Vizier Talaat Pasha visited both Berlin, and Sofia, in September 1918, and came away with the understanding that the war was no longer winnable. With Germany likely seeking a separate peace, the Ottomans would be forced to as well. Grand Vizier Talaat convinced the other members of the ruling party that they must resign, as the Allies would impose far harsher terms if they thought the people who started the war were still in power. He also sought out the United States to see if he could surrender to them and gain the benefits of the Fourteen Points despite the Ottoman Empire and the United States not being at war; however, the Americans never responded, as they were waiting on British advice as to how to respond which never came. On 13 October, Talaat and the rest of his ministry resigned. Ahmed Izzet Pasha replaced Talaat as Grand Vizier.

text: Two days after taking office, Ahmed Izzet Pasha sent the captured British General Charles Vere Ferrers Townshend to the Allies to seek terms on an armistice.[27] The British Cabinet were eager to negotiate a deal. British government interpreted that not only should Britain conduct the negotiations, but should conduct them alone. There may be a desire to cut the French out of territorial "spoils" promised to them in the Sykes-Picot agreement. Talaat (before resigning) had sent an emissary to the French as well, but that emissary had been slower to respond back. The British cabinet empowered Admiral Calthorpe to conduct the negotiations, and to explicitly exclude the French from them.[27] The negotiations began on Sunday, 27 October on the HMS Agamemnon, a British battleship. The British refused to admit French Vice-Admiral Jean Amet, the senior French naval officer in the area, despite his desire to join; the Ottoman delegation, headed by Minister of Marine Affairs Rauf Bey.[27]

text: Unknown to both sides, both sides were actually quite eager to sign a deal and willing to give up their objectives to do so. The British delegation had been given a list of 24 demands, but were told to concede on any of them except allowing the occupation of the forts on the Dardanelles as well as free passage through the Bosphorus; the British desired access to the Black Sea for the Rumanian front. Prime Minister David Lloyd George also desired to make a deal quickly before the United States could step in; according to the diary of Maurice Hankey:

text: [Lloyd George] was also very contemptuous of President Wilson and anxious to arrange the division of Empire between France, Italy, and G.B. before speaking to America. He also thought it would attract less attention to our enormous gains during the war if we swallowed our share of Empire now, and the German colonies later.[27]

text: The Ottomans, for their part, believed the war to be lost and would have accepted almost any demands placed on them. As a result, the initial draft prepared by the British was accepted largely unchanged; the Ottomans did not know they could have pushed back on most of the clauses, and the British did not know they could have demanded even more. The Ottomans ceded the rights to the Allies to occupy "in case of disorder" any Ottoman territory, a vague and broad clause.[27] The French were displeased with the precedent; French Premier Clemenceau disliked the British making unilateral decisions in so important a matter. Lloyd George countered that the French had concluded a similar armistice on short notice in the Armistice of Salonica which had been negotiated by French General d'Esperey, and that Great Britain (and Czarist Russia) had committed the vast majority of troops to the campaign against the Ottomans. The French agreed to accept the matter as closed.

text: On 30 October 1918, the Armistice of Mudros was signed, ending Ottoman involvement in World War 1. The Ottoman public, however, was given misleadingly positive impressions of the severity of the terms of the Armistice. They thought its terms were considerably more lenient than they actually were, a source of discontent later that the Allies had betrayed the offered terms.[27]

text: Genocide[edit]

text: During WWI the Ottoman Empire engaged in a genocide against local ethnicities in its territory. The Armenian Genocide,[32] also known as the Armenian Holocaust,[33] was the Ottoman government's systematic extermination of 1.5 million Christian Armenians, mostly Ottoman citizens within the Ottoman Empire and its successor state, the Republic of Turkey.[34][35] The starting date is conventionally held to be 24 April 1915, the day that Ottoman authorities rounded up, arrested, and deported 235 to 270 Armenian intellectuals and community leaders from Constantinople to Ankara, the majority of whom were eventually murdered. The genocide was carried out during and after World War I and implemented in two phases: the wholesale killing of the able-bodied male population through massacre and subjection of army conscripts to forced labour, followed by the deportation of women, children, the elderly, and the infirm on death marches leading to the Syrian desert. Driven forward by military escorts, the deportees were deprived of food and water and subjected to periodic robbery, rape, and massacre.[36][37][38] Other indigenous and Christian ethnic groups such as the Assyrians and the Ottoman Greeks were similarly targeted for extermination by the Ottoman government in the Assyrian genocide and the Greek genocide, and their treatment is considered by some historians to be part of the same genocidal policy.[39][40] Most Armenian diaspora communities around the world came into being as a direct result of the genocide.[41]

text: Raphael Lemkin was explicitly moved by the Armenian annihilation to define systematic and premeditated exterminations within legal parameters and to coin the word genocide in 1943.[42] The Armenian Genocide is acknowledged to have been one of the first modern genocides,[43][44][45] because scholars point to the organized manner in which the killings were carried out in order to eliminate the Armenians, and it is the second most-studied case of genocide after the Holocaust.[46]

text: Turkey, the successor state of the Ottoman Empire, denies the word genocide as an accurate term for the mass killings of Armenians that began under Ottoman rule in 1915. It has in recent years been faced with repeated calls to recognize them as genocide.[47] To date, 29 countries have officially recognized the mass killings as genocide,[48] as have most genocide scholars and historians.[49][50][51]

text: Notes[edit]

text:
Jump up ^ Sazonov’s commitment to a two-front war and disregard for Yudenich’s warnings to seek peace with the Ottomans had overstretched Russia.[20]
Jump up ^ The reference "voluntary and honest union" realized with the Soviet Union, as the 11th Red Army had its virtually unopposed advance to the region on 29 November 1920.
Jump up ^ Hovhannes Katchaznouni was in city of Van until 1914. He was on the Armenian delegation that conducted peace talks at Trabzon and Batoum negotiations with the Empire.

tag: ol

text: Includes most of to daysader nation of Europe


document_title: Serial ATA

question_text: what is the transfer speed for sata 1

question_tokens: what is the transfer speed for sata 1

root

text: Serial ATA

text: Features[edit]

text: Hotplug[edit]

text: The Serial ATA Spec requirements for SATA device hot plugging, that is, devices and motherboards that meet the specification are capable of insertion / removal of a device into / from a backplane connector (combined signal and power) that has power on. After insertion, both the Device and Host initialize and then operate normally. The powered Host or Device is not necessarily in a quiescent state.

tag: p

text: Unlike PATA, both SATA and eSATA support hotplugging by design. However, this feature requires proper support at the host, device (drive), and operating-system levels. In general, all SATA devices (drives) support hotplugging (due to the requirements on the device-side), also most SATA host adapters support this function.[1]

text: Advanced Host Controller Interface[edit]

text: Advanced Host Controller Interface (AHCI) is an open host controller interface published and used by Intel, which has become a de facto standard. It allows the use of advanced features of SATA such as hotplug and native command queuing (NCQ). If AHCI is not enabled by the motherboard and chipset, SATA controllers typically operate in "IDE[b] emulation" mode, which does not allow access to device features not supported by the ATA (also called IDE) standard.

text: Windows device drivers that are labeled as SATA are often running in IDE emulation mode unless they explicitly state that they are AHCI mode, in RAID mode, or a mode provided by a proprietary driver and command set that allowed access to SATA's advanced features before AHCI became popular. Modern versions of Microsoft Windows, Mac OS X, FreeBSD, Linux with version 2.6.19 onward,[10] as well as Solaris and OpenSolaris, include support for AHCI, but older operating systems such as Windows XP do not. Even in those instances, a proprietary driver may have been created for a specific chipset, such as Intel's.[11]

text: Revisions[edit]

text: SATA revisions are often designated with a dash followed by roman numerals, e.g. "SATA-III",[12] to avoid confusion with the speed, which is always displayed in Arabic numerals, e.g. "SATA 6 Gbit/s".

text: SATA revision 1.0 (1.5 Gbit/s, 150 MB/s, Serial ATA-150)[edit]

text: Revision 1.0a[2] was released on January 7, 2003. First-generation SATA interfaces, now known as SATA 1.5 Gbit/s, communicate at a rate of 1.5 Gbit/s,[c] and do not support Native Command Queuing (NCQ). Taking 8b/10b encoding overhead into account, they have an actual uncoded transfer rate of 1.2 Gbit/s (150 MB/s). The theoretical burst throughput of SATA 1.5 Gbit/s is similar to that of PATA/133, but newer SATA devices offer enhancements such as NCQ, which improve performance in a multitasking environment.

text: During the initial period after SATA 1.5 Gbit/s finalization, adapter and drive manufacturers used a "bridge chip" to convert existing PATA designs for use with the SATA interface. Bridged drives have a SATA connector, may include either or both kinds of power connectors, and, in general, perform identically to their native-SATA equivalents.[13] However, most bridged drives lack support for some SATA-specific features such as NCQ. Native SATA products quickly took over the bridged products with the introduction of the second generation of SATA drives.[citation needed]

text: As of April 2010[update], the fastest 10,000 rpm SATA hard disk drives could transfer data at maximum (not average) rates of up to 157 MB/s,[14] which is beyond the capabilities of the older PATA/133 specification and also exceeds the capabilities of SATA 1.5 Gbit/s.

text: SATA revision 2.0 (3 Gbit/s, 300 MB/s, Serial ATA-300)[edit]

text: SATA revision 2.0 was released in April 2004, introducing Native Command Queuing (NCQ). It is backward compatible with SATA 1.5 Gbit/s.[15]

text: Second-generation SATA interfaces run with a native transfer rate of 3.0 Gbit/s that, when accounted for the 8b/10b encoding scheme, equals to the maximum uncoded transfer rate of 2.4 Gbit/s (300 MB/s). The theoretical burst throughput of the SATA revision 2.0, which is also known as the SATA 3 Gbit/s, doubles the throughput of SATA revision 1.0.

text: All SATA data cables meeting the SATA spec are rated for 3.0 Gbit/s and handle modern mechanical drives without any loss of sustained and burst data transfer performance. However, high-performance flash-based drives can exceed the SATA 3 Gbit/s transfer rate; this is addressed with the SATA 6 Gbit/s interoperability standard.

text: SATA revision 2.5[edit]

text: Announced in August 2005, SATA revision 2.5 consolidated the specification to a single document.[16][17]

text: SATA revision 2.6[edit]

text: This section needs expansion. You can help by adding to it. (November 2017)

text: Announced in February 2007, SATA revision 2.6 introduced the following features:[18]

text: Slimline connector.

text: SATA revision 3.0 (6 Gbit/s, 600 MB/s, Serial ATA-600)[edit]

text: Serial ATA International Organization (SATA-IO) presented the draft specification of SATA 6 Gbit/s physical layer in July 2008,[19] and ratified its physical layer specification on August 18, 2008.[20] The full 3.0 standard was released on May 27, 2009.[21]

text: Third-generation SATA interfaces run with a native transfer rate of 6.0 Gbit/s; taking 8b/10b encoding into account, the maximum uncoded transfer rate is 4.8 Gbit/s (600 MB/s). The theoretical burst throughput of SATA 6.0 Gbit/s is double that of SATA revision 2.0. It is backward compatible with SATA 3 Gbit/s.[15]

text: The SATA 3.0 specification contains the following changes:

text:
6 Gbit/s for scalable performance.
Continued compatibility with SAS, including SAS 6 Gbit/s, as per "a SAS domain may support attachment to and control of unmodified SATA devices connected directly into the SAS domain using the Serial ATA Tunneled Protocol (STP)" from the SATA Revision 3.0 Gold specification.
Isochronous Native Command Queuing (NCQ) streaming command to enable isochronous quality of service data transfers for streaming digital content applications.
An NCQ management feature that helps optimize performance by enabling host processing and management of outstanding NCQ commands.
Improved power management capabilities.
A small low insertion force (LIF) connector for more compact 1.8-inch storage devices.
A 7 mm optical disk drive profile for the slimline SATA connector (in addition to the existing 12.7 mm and 9.5 mm profiles).
Alignment with the INCITS ATA8-ACS standard.

text: In general, the enhancements are aimed at improving quality of service for video streaming and high-priority interrupts. In addition, the standard continues to support distances up to one meter. The newer speeds may require higher power consumption for supporting chips, though improved process technologies and power management techniques may mitigate this. The later specification can use existing SATA cables and connectors, though it was reported in 2008 that some OEMs were expected to upgrade host connectors for the higher speeds.[22]

text: SATA revision 3.1[edit]

text: Released in July 2011, SATA revision 3.1 introduced or changed the following features:[23][24]

text:
mSATA, SATA for solid-state drives in mobile computing devices, a PCI Express Mini Card-like connector that is electrically SATA.[25]
Zero-power optical disk drive, idle SATA optical drive draws no power.
Queued TRIM Command, improves solid-state drive performance.
Required Link Power Management, reduces overall system power demand of several SATA devices.
Hardware Control Features, enable host identification of device capabilities.
Universal Storage Module (USM), a new standard for cableless plug-in (slot) powered storage for consumer electronics devices.[26][27]

text: SATA revision 3.2 (16 Gbit/s, 1969 MB/s)[edit]

text: Released in August 2013, SATA revision 3.2 introduced the following features:[28]

text:
The SATA Express specification defines an interface that combines both SATA and PCI Express buses, making it possible for legacy SATA and PCI Express storage devices to coexist; see the SATA Express section below for a more detailed summary.[29][30]
The SATA M.2 standard is a small form factor implementation of the SATA Express interface, with the addition of an internal USB 3.0 port; see the M.2 (NGFF) section below for a more detailed summary.[31]
microSSD introduces a ball grid array electrical interface for miniaturized, embedded SATA storage.[32]
USM Slim reduces thickness of Universal Storage Module (USM) from 14.5 millimetres (0.57 inches) to 9 millimetres (0.35 inches).[33]
DevSleep enables lower power consumption for always-on devices while they are in low-power modes such as InstantGo (which used to be known as Connected Standby).[34]
Hybrid Information provides higher performance for solid-state hybrid drives.[35][36]

text: SATA revision 3.3[edit]

text: Released in February 2016, SATA revision 3.3 introduced the following features:[37][38]

text:
Shingled Magnetic Recording (SMR) support that provides a 25 percent or greater increase in hard disk drive capacity by overlapping tracks on the media.
Power Disable feature allows for remote power cycling of SATA drives and a Rebuild Assist function that speeds up the rebuild process to help ease maintenance in the data center.
Transmitter Emphasis Specification increases interoperability and reliability between host and devices in electrically demanding environments.
An activity indicator and staggered spin-up can be controlled by the same pin, adding flexibility and providing users with more choices.

text: The new Power Disable feature (similar to the SAS Power Disable feature) uses Pin 3 of the SATA power connector. Some legacy power supplies that provide 3.3V power on Pin 3 would force drives with Power Disable feature to get stuck in a hard reset condition preventing them from spinning up. The problem can usually be eliminated by using a simple “Molex to SATA” power adaptor to supply power to these drives.[39]

text: Cables, connectors, and ports[edit]

text: Connectors and cables present the most visible differences between SATA and parallel ATA drives. Unlike PATA, the same connectors are used on 3.5-inch (89 mm) SATA hard disks (for desktop and server computers) and 2.5-inch (64 mm) disks (for portable or small computers).[40]

text: Standard SATA connectors for both data and power have a conductor pitch of 1.27 mm (0.050 inches). Low insertion force is required to mate a SATA connector. A smaller mini-SATA or mSATA connector is used by smaller devices such as 1.8-inch SATA drives, some DVD and Blu-ray drives, and mini SSDs.[41]

text: A special eSATA connector is specified for external devices, and an optionally implemented provision for clips to hold internal connectors firmly in place. SATA drives may be plugged into SAS controllers and communicate on the same physical cable as native SAS disks, but SATA controllers cannot handle SAS disks.

text: Female SATA ports (on motherboards for example) are for use with SATA data cables that have locks or clips to prevent accidental unplugging. Some SATA cables have right- or left-angled connectors to ease connection to circuit boards.

text: Data connector[edit]

text:
Standard connector, data segment[42]

Pin #
Mating
Function

1
1st
Ground

2
2nd
A+ (transmit)

3
2nd
A− (transmit)

4
1st
Ground

5
2nd
B− (receive)

6
2nd
B+ (receive)

7
1st
Ground

 —
Coding notch

text: The SATA standard defines a data cable with seven conductors (three grounds and four active data lines in two pairs) and 8 mm wide wafer connectors on each end. SATA cables can have lengths up to 1 metre (3.3 ft), and connect one motherboard socket to one hard drive. PATA ribbon cables, in comparison, connect one motherboard socket to one or two hard drives, carry either 40 or 80 wires, and are limited to 45 centimetres (18 in) in length by the PATA specification; however, cables up to 90 centimetres (35 in) are readily available. Thus, SATA connectors and cables are easier to fit in closed spaces and reduce obstructions to air cooling. Although they are more susceptible to accidental unplugging and breakage than PATA, users can purchase cables that have a locking feature, whereby a small (usually metal) spring holds the plug in the socket.

text: SATA connectors may be straight, right-angled, or left angled. Angled connectors allow lower-profile connections. Right-angled (also called 90-degree) connectors lead the cable immediately away from the drive, on the circuit-board side. Left-angled (also called 270-degree) connectors lead the cable across the drive towards its top.

text: One of the problems associated with the transmission of data at high speed over electrical connections is described as noise, which is due to electrical coupling between data circuits and other circuits. As a result, the data circuits can both affect other circuits and be affected by them. Designers use a number of techniques to reduce the undesirable effects of such unintentional coupling. One such technique used in SATA links is differential signaling. This is an enhancement over PATA, which uses single-ended signaling. The use of fully shielded twin-ax conductors, with multiple ground connections, for each differential pair improves isolation between the channels and reduces the chances of lost data in difficult electrical environments.

text:
A seven-pin SATA data cable (left-angled version of the connector)

SATA connector on a 3.5-inch hard drive, with data pins on the left and power pins on the right. The two different pin lengths ensure a specific mating order; the longer lengths are ground pins and make contact first.

SATA 3.0 (6 Gbit/s) cable showing fully shielded twin-ax pairs

text: Power connectors[edit]

text: Standard connector[edit]

text:
Standard connector, power segment

Pin #
Mating
Function

 —
Coding notch

1
3rd
3.3 V Power

2
3rd

3
2nd
Enter/exit Power Disable (PWDIS) mode
(3.3 V Power, Pre-charge prior to SATA 3.3)

4
1st
Ground

5
2nd

6
2nd

7
2nd
5 V Power, Pre-charge

8
3rd
5 V Power

9
3rd

10
2nd
Ground

11
3rd
Staggered spinup/activity
(in supporting drives)

12
1st
Ground

13
2nd
12 V Power, Pre-charge

14
3rd
12 V Power

15
3rd

text: SATA specifies a different power connector than the four-pin Molex connector used on Parallel ATA (PATA) devices (and earlier small storage devices, going back to ST-506 hard disk drives and even to floppy disk drives that predated the IBM PC). It is a wafer-type connector, like the SATA data connector, but much wider (fifteen pins versus seven) to avoid confusion between the two. Some early SATA drives included the four-pin Molex power connector together with the new fifteen-pin connector, but most SATA drives now have only the latter.

text: The new SATA power connector contains many more pins for several reasons:[43]

text:
3.3 V is supplied along with the traditional 5 V and 12 V supplies. However, very few drives actually use it, so they may be powered from a four-pin Molex connector with an adapter.
Pin 3 in SATA revision 3.3 has been redefined as PWDIS and is used to enter and exit the POWER DISABLE mode for compatibility with SAS specification. If Pin 3 is driven HIGH (2.1–3.6 V max), power to the drive circuitry is disabled. Drives with this feature do not power up in systems designed to SATA revision 3.1 or earlier. This is because Pin 3 driven HIGH prevents the drive from powering up.[39]
To reduce impedance and increase current capability, each voltage is supplied by three pins in parallel, though one pin in each group is intended for precharging (see below). Each pin should be able to carry 1.5 A.
Five parallel pins provide a low-impedance ground connection.
Two ground pins and one pin for each supplied voltage support hot-plug precharging. Ground pins 4 and 12 in a hot-swap cable are the longest, so they make contact first when the connectors are mated. Drive power connector pins 3, 7, and 13 are longer than the others, so they make contact next. The drive uses them to charge its internal bypass capacitors through current-limiting resistances. Finally, the remaining power pins make contact, bypassing the resistances and providing a low-impedance source of each voltage. This two-step mating process avoids glitches to other loads and possible arcing or erosion of the SATA power-connector contacts.
Pin 11 can function for staggered spinup, activity indication, both, or nothing. It is an open-collector signal, which may be pulled down by the connector or the drive. If pulled down at the connector (as it is on most cable-style SATA power connectors), the drive spins up as soon as power is applied. If left floating, the drive waits until it is spoken to. This prevents many drives from spinning up simultaneously, which might draw too much power. The pin is also pulled low by the drive to indicate drive activity. This may be used to give feedback to the user through an LED.

text: Passive adapters are available that convert a four-pin Molex connector to a SATA power connector, providing the 5 V and 12 V lines available on the Molex connector, but not 3.3 V. There are also four-pin Molex-to-SATA power adapters that include electronics to additionally provide the 3.3 V power supply.[44] However, most drives do not require the 3.3 V power line.[45]

text: Slimline connector[edit]

text:
Slimline connector, power segment

Pin #
Mating
Function

 —
Coding notch

1
3rd
Device presence

2
2nd
5 V Power

3
2nd

4
2nd
Manufacturing diagnostic

5
1st
Ground

6
1st

text: SATA 2.6 is the first revision that defined the slimline connector, intended for smaller form-factors such as notebook optical drives. Pin 1 of the slimline signal connector, denoting device presence, is shorter than the others to allow hot-swapping. The slimline signal connector is identical and compatible with the standard version, while the power connector is reduced to six pins so it supplies only +5 V, and not +12 V or +3.3 V.[18][46]

text: Low-cost adapters exist to convert from standard SATA to slimline SATA.

text:
A six-pin slimline SATA power connector

The back of a SATA-based slimline optical drive

text: Micro connector[edit]

text:
Micro connector, power segment

Pin #
Mating
Function

1
3rd
3.3 V Power

2
2nd

3
1st
Ground

4
1st

5
2nd
5 V Power

6
3rd

7
3rd
Reserved

 —
Coding notch

8
3rd
Vendor specific

9
2nd

text: The micro SATA connector (sometimes called uSATA or μSATA[47]) originated with SATA 2.6, and is intended for 1.8-inch (46 mm) hard disk drives. There is also a micro data connector, similar in appearance but slightly thinner than the standard data connector.

text: eSATA[edit]

text: Standardized in 2004, eSATA (e standing for external) provides a variant of SATA meant for external connectivity. It uses a more robust connector, longer shielded cables, and stricter (but backward-compatible) electrical standards. The protocol and logical signaling (link/transport layers and above) are identical to internal SATA. The differences are:

text:
Minimum transmit amplitude increased: Range is 500–600 mV instead of 400–600 mV.
Minimum receive amplitude decreased: Range is 240–600 mV instead of 325–600 mV.
Maximum cable length increased to 2 metres (6.6 ft) from 1 metre (3.3 ft).
The eSATA cable and connector is similar to the SATA 1.0a cable and connector, with these exceptions:

The eSATA connector is mechanically different to prevent unshielded internal cables from being used externally. The eSATA connector discards the "L"-shaped key and changes the position and size of the guides.
The eSATA insertion depth is deeper: 6.6 mm instead of 5 mm. The contact positions are also changed.
The eSATA cable has an extra shield to reduce EMI to FCC and CE requirements. Internal cables do not need the extra shield to satisfy EMI requirements because they are inside a shielded case.
The eSATA connector uses metal springs for shield contact and mechanical retention.
The eSATA connector has a design-life of 5,000 matings; the ordinary SATA connector is only specified for 50.

text: Aimed at the consumer market, eSATA enters an external storage market served also by the USB and FireWire interfaces. The SATA interface has certain advantages. Most external hard-disk-drive cases with FireWire or USB interfaces use either PATA or SATA drives and "bridges" to translate between the drives' interfaces and the enclosures' external ports; this bridging incurs some inefficiency. Some single disks can transfer 157 MB/s during real use,[14] about four times the maximum transfer rate of USB 2.0 or FireWire 400 (IEEE 1394a) and almost twice as fast as the maximum transfer rate of FireWire 800. The S3200 FireWire 1394b specification reaches around 400 MB/s (3.2 Gbit/s), and USB 3.0 has a nominal speed of 5 Gbit/s. Some low-level drive features, such as S.M.A.R.T., may not operate through some USB[48] or FireWire or USB+FireWire bridges; eSATA does not suffer from these issues provided that the controller manufacturer (and its drivers) presents eSATA drives as ATA devices, rather than as SCSI devices, as has been common with Silicon Image, JMicron, and NVIDIA nForce drivers for Windows Vista. In those cases SATA drives do not have low-level features accessible.

text: The eSATA version of SATA 6G operates at 6.0 Gbit/s (the term "SATA III" is avoided by the SATA-IO organization to prevent confusion with SATA II 3.0 Gbit/s, which was colloquially referred to as "SATA 3G" [bit/s] or "SATA 300" [MB/s] since the 1.5 Gbit/s SATA I and 1.5 Gbit/s SATA II were referred to as both "SATA 1.5G" [bit/s] or "SATA 150" [MB/s]). Therefore, eSATA connections operate with negligible differences between them.[49] Once an interface can transfer data as fast as a drive can handle them, increasing the interface speed does not improve data transfer.

text: There are some disadvantages, however, to the eSATA interface:

text:
Devices built before the eSATA interface became popular lack external SATA connectors.
For small form-factor devices (such as external 2.5-inch (64 mm) disks), a PC-hosted USB or FireWire link can usually supply sufficient power to operate the device. However, eSATA connectors cannot supply power, and require a power supply for the external device. The related eSATAp (but mechanically incompatible, sometimes called eSATA/USB) connector adds power to an external SATA connection, so that an additional power supply is not needed.[50]

text: As of mid 2017 few new computers have dedicated external SATA (eSATA) connectors, with USB3 dominating and USB3 Type C, often with the Thunderbolt replacement for the Lightning standard, starting to replace the earlier USB connectors. Still sometimes present are single ports supporting both USB3 and eSATA.

text: Desktop computers without a built-in eSATA interface can install an eSATA host bus adapter (HBA); if the motherboard supports SATA, an externally available eSATA connector can be added. Notebook computers with the now rare Cardbus[51] or ExpressCard[52] could add an eSATA HBA. With passive adapters, the maximum cable length is reduced to 1 metre (3.3 ft) due to the absence of compliant eSATA signal-levels.

text: eSATAp[edit]

text: eSATAp stands for powered eSATA. It is also known as Power over eSATA, Power eSATA, eSATA/USB Combo, or eSATA USB Hybrid Port (EUHP). An eSATAp port combines the four pins of the USB 2.0 (or earlier) port, the seven pins of the eSATA port, and optionally two 12 V power pins.[53] Both SATA traffic and device power are integrated in a single cable, as is the case with USB but not eSATA. The 5 V power is provided through two USB pins, while the 12 V power may optionally be provided. Typically desktop, but not notebook, computers provide 12 V power, so can power devices requiring this voltage, typically 3.5-inch disk and CD/DVD drives, in addition to 5 V devices such as 2.5-inch drives.

text: Both USB and eSATA devices can be used with an eSATAp port, when plugged in with a USB or eSATA cable, respectively. An eSATA device cannot be powered via an eSATAp cable, but a special cable can make both SATA or eSATA and power connectors available from an eSATAp port.

text: An eSATAp connector can be built into a computer with internal SATA and USB, by fitting a bracket with connections for internal SATA, USB, and power connectors and an externally accessible eSATAp port. Though eSATAp connectors have been built into several devices, manufacturers do not refer to an official standard.

text: Pre-standard implementations[edit]

text:
Prior to the final eSATA 3 Gbit/s specification, a number of products were designed for external connection of SATA drives. Some of these use the internal SATA connector, or even connectors designed for other interface specifications, such as FireWire. These products are not eSATA compliant. The final eSATA specification features a specific connector designed for rough handling, similar to the regular SATA connector, but with reinforcements in both the male and female sides, inspired by the USB connector. eSATA resists inadvertent unplugging, and can withstand yanking or wiggling, which could break a male SATA connector (the hard-drive or host adapter, usually fitted inside the computer). With an eSATA connector, considerably more force is needed to damage the connector—and if it does break, it is likely to be the female side, on the cable itself,[citation needed] which is relatively easy to replace.
Prior to the final eSATA 6 Gbit/s specification many add-on cards and some motherboards advertised eSATA 6 Gbit/s support because they had 6 Gbit/s SATA 3.0 controllers for internal-only solutions. Those implementations are non-standard, and eSATA 6 Gbit/s requirements were ratified in the July 18, 2011 SATA 3.1 specification.[54] Some products might not be fully eSATA 6 Gbit/s compliant.

text: Mini-SATA (mSATA)[edit]

text: Mini-SATA (abbreviated as mSATA), which is distinct from the micro connector,[47] was announced by the Serial ATA International Organization on September 21, 2009.[55] Applications include netbooks, laptops and other devices that require a solid-state drive in a small footprint.

text: The connector is similar in appearance to a PCI Express Mini Card interface,[56] but is not electrically compatible; the data signals (TX±/RX± SATA, PETn0 PETp0 PERn0 PERp0 PCI Express) need a connection to the SATA host controller instead of the PCI Express host controller.

text: SFF-8784 connector[edit]

text:
SFF-8784 connector[57]

Bottom
Top

Pin
Function
Pin
Function
Pin
Function
Pin
Function

1
Ground
6
Unused
11
Ground
16
+5 V

2
Ground
7
+5 V
12
B+ (transmit)
17
Ground

3
Ground
8
Unused
13
B− (transmit)
18
A− (receive)

4
Ground[d]
9
Unused
14
Ground
19
A+ (receive)

5
LED
10
Ground
15
+5 V
20
Ground

text: Slim 2.5-inch SATA devices, 5 mm (0.20 inches) in height, use the twenty-pin SFF-8784 edge connector to save space. By combining the data signals and power lines into a slim connector that effectively enables direct connection to the device's printed circuit board (PCB) without additional space-consuming connectors, SFF-8784 allows further internal layout compaction for portable devices such as ultrabooks.[57]

text: Pins 1 to 10 are on the connector's bottom side, while pins 11 to 20 are on the top side.[57]

text: SATA Express[edit]

text: SATA Express, initially standardized in the SATA 3.2 specification,[58] is an interface that supports either SATA or PCI Express storage devices. The host connector is backward compatible with the standard 3.5-inch SATA data connector, allowing up to two legacy SATA devices to connect.[59] At the same time, the host connector provides up to two PCI Express 3.0 lanes as a pure PCI Express connection to the storage device, allowing bandwidths of up to 2 GB/s.[28][60]

text: Instead of the otherwise usual approach of doubling the native speed of the SATA interface, PCI Express was selected for achieving data transfer speeds greater than 6 Gbit/s. It was concluded that doubling the native SATA speed would take too much time, too many changes would be required to the SATA standard, and would result in a much greater power consumption when compared to the existing PCI Express bus.[61]

text: In addition to supporting legacy Advanced Host Controller Interface (AHCI), SATA Express also makes it possible for NVM Express (NVMe) to be used as the logical device interface for connected PCI Express storage devices.[62]

text: M.2 (NGFF)[edit]

text: M.2, formerly known as the Next Generation Form Factor (NGFF), is a specification for computer expansion cards and associated connectors. It replaces the mSATA standard, which uses the PCI Express Mini Card physical layout. Having a smaller and more flexible physical specification, together with more advanced features, the M.2 is more suitable for solid-state storage applications in general, especially when used in small devices like ultrabooks or tablets.[63]

text: The M.2 standard is designed as a revision and improvement to the mSATA standard, so that larger printed circuit boards (PCBs) can be manufactured. While mSATA took advantage of the existing PCI Express Mini Card form factor and connector, M.2 has been designed to maximize usage of the card space, while minimizing the footprint.[63][64][65]

text: Supported host controller interfaces and internally provided ports are a superset to those defined by the SATA Express interface. Essentially, the M.2 standard is a small form factor implementation of the SATA Express interface, with the addition of an internal USB 3.0 port.[63]

text: U.2 (SFF-8639)[edit]

text: U.2, formerly known as SFF-8639. Like its predecessor it carries a PCI Express electrical signal, however U.2 uses a PCIe 3.0 ×4 link providing a higher bandwidth of 32 Gbit/s in each direction.

text: Protocol[edit]

text: This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (January 2016) (Learn how and when to remove this template message)

text: The SATA specification defines three distinct protocol layers: physical, link, and transport.

text: Physical layer[edit]

text: The physical layer defines SATA's electrical and physical characteristics (such as cable dimensions and parasitics, driver voltage level and receiver operating range), as well as the physical coding subsystem (bit-level encoding, device detection on the wire, and link initialization).

text: Physical transmission uses differential signaling. The SATA PHY contains a transmit pair and receive pair. When the SATA-link is not in use (example: no device attached), the transmitter allows the transmit pins to float to their common-mode voltage level. When the SATA-link is either active or in the link-initialization phase, the transmitter drives the transmit pins at the specified differential voltage (1.5 V in SATA/I).

text: SATA physical coding uses a line encoding system known as 8b/10b encoding. This scheme serves multiple functions required to sustain a differential serial link. First, the stream contains necessary synchronization information that allows the SATA host/drive to extract clocking. The 8b/10b encoded sequence embeds periodic edge transitions to allow the receiver to achieve bit-alignment without the use of a separately transmitted reference clock waveform. The sequence also maintains a neutral (DC-balanced) bitstream, which lets transmit drivers and receiver inputs be AC-coupled. Generally, the actual SATA signalling is half-duplex, meaning that it can only read or write data at any one time.

text: Also, SATA uses some of the special characters defined in 8b/10b. In particular, the PHY layer uses the comma (K28.5) character to maintain symbol-alignment. A specific four-symbol sequence, the ALIGN primitive, is used for clock rate-matching between the two devices on the link. Other special symbols communicate flow control information produced and consumed in the higher layers (link and transport).

text: Separate point-to-point AC-coupled low-voltage differential signaling (LVDS) links are used for physical transmission between host and drive.

text: The PHY layer is responsible for detecting the other SATA/device on a cable, and link initialization. During the link-initialization process, the PHY is responsible for locally generating special out-of-band signals by switching the transmitter between electrical-idle and specific 10b-characters in a defined pattern, negotiating a mutually supported signalling rate (1.5, 3.0, or 6.0 Gbit/s), and finally synchronizing to the far-end device's PHY-layer data stream. During this time, no data is sent from the link-layer.

text: Once link-initialization has completed, the link-layer takes over data-transmission, with the PHY providing only the 8b/10b conversion before bit transmission.

text: Link layer[edit]

text: After the PHY-layer has established a link, the link layer is responsible for transmission and reception of Frame Information Structures (FISs) over the SATA link. FISs are packets containing control information or payload data. Each packet contains a header (identifying its type), and payload whose contents are dependent on the type. The link layer also manages flow control over the link.

text: Transport layer[edit]

text: Layer number three in the serial ATA specification is the transport layer. This layer has the responsibility of acting on the frames and transmitting/receiving the frames in an appropriate sequence. The transport layer handles the assembly and disassembly of FIS structures, which includes, for example, extracting content from register FISs into the task-file and informing the command layer. In an abstract fashion, the transport layer is responsible for creating and encoding FIS structures requested by the command layer, and removing those structures when the frames are received.

text: When DMA data is to be transmitted and is received from the higher command layer, the transport layer appends the FIS control header to the payload, and informs the link layer to prepare for transmission. The same procedure is performed when data is received, but in reverse order. The link layer signals to the transport layer that there is incoming data available. Once the data is processed by the link layer, the transport layer inspects the FIS header and removes it before forwarding the data to the command layer.

text: Topology[edit]

text: SATA uses a point-to-point architecture. The physical connection between a controller and a storage device is not shared among other controllers and storage devices. SATA defines multipliers, which allows a single SATA controller port to drive up to fifteen storage devices. The multiplier performs the function of a hub; the controller and each storage device is connected to the hub.[66] This is conceptually similar to SAS expanders.

text: Modern[update] PC systems have SATA controllers built into the motherboard, typically featuring two to eight ports. Additional ports can be installed through add-in SATA host adapters (available in variety of bus-interfaces: USB, PCI, PCIe).

text: Backward and forward compatibility[edit]

text: SATA and PATA[edit]

text: At the device level, SATA and PATA (Parallel AT Attachment) devices remain completely incompatible—they cannot be interconnected. At the application level, SATA devices can be specified to look and act like PATA devices.[67] Many motherboards offer a "legacy mode" option, which makes SATA drives appear to the OS like PATA drives on a standard controller. This eases OS installation by not requiring that a specific driver be loaded during setup, but sacrifices support for some features of SATA and, in general, disables some of the boards' PATA or SATA ports, since the standard PATA controller interface supports only four drives. (Often, which ports are disabled is configurable.)

text: The common heritage of the ATA command set has enabled the proliferation of low-cost PATA to SATA bridge chips. Bridge chips were widely used on PATA drives (before the completion of native SATA drives) as well in standalone converters. When attached to a PATA drive, a device-side converter allows the PATA drive to function as a SATA drive. Host-side converters allow a motherboard PATA port to connect to a SATA drive.

text: The market has produced powered enclosures for both PATA and SATA drives that interface to the PC through USB, Firewire or eSATA, with the restrictions noted above. PCI cards with a SATA connector exist that allow SATA drives to connect to legacy systems without SATA connectors.

text: SATA 1.5 Gbit/s and SATA 3 Gbit/s[edit]

text: The designers of SATA aimed for backward and forward compatibility with future revisions of the SATA standard.[citation needed] To prevent interoperability problems that could occur when next generation SATA drives are installed on motherboards with standard legacy SATA 1.5 Gbit/s host controllers, many manufacturers have made it easy to switch those newer drives to the previous standard's mode. For example, Seagate/Maxtor has added a user-accessible jumper-switch, known as the force 150, to enable the drive switch between forced 1.5 Gbit/s and 1.5/3 Gbit/s negotiated operation. Western Digital uses a jumper setting called OPT1 enabled to force 1.5 Gbit/s data transfer speed (OPT1 is enabled by putting the jumper on pins 5 and 6). Samsung drives can be forced to 1.5 Gbit/s mode using software that may be downloaded from the manufacturer's website. Configuring some Samsung drives in this manner requires the temporary use of a SATA-2 (SATA 3.0 Gbit/s) controller while programming the drive.

text: The force 150 switch (or equivalent) is also useful for attaching SATA 3 Gbit/s hard drives to SATA controllers on PCI cards, since many of these controllers (such as the Silicon Image chips) run at 3 Gbit/s, even though the PCI bus cannot reach 1.5 Gbit/s speeds. This can cause data corruption in operating systems that do not specifically test for this condition and limit the disk transfer speed.[citation needed]

text: SATA 3 Gbit/s and SATA 6 Gbit/s[edit]

text: This section needs expansion. You can help by adding to it. (October 2011)

text: SATA 3 Gbit/s and SATA 6 Gbit/s are compatible with each other. Most devices that are only SATA 3 Gbit/s can connect with devices that are SATA 6 Gbit/s, and vice versa, though SATA 3 Gbit/s devices only connect with SATA 6 Gbit/s devices at the slower 3 Gbit/s speed.

text: SATA 1.5 Gbit/s and SATA 6 Gbit/s[edit]

text: This section needs expansion. You can help by adding to it. (July 2013)

text: SATA 1.5 Gbit/s and SATA 6 Gbit/s are compatible with each other. Most devices that are only SATA 1.5 Gbit/s can connect with devices that are SATA 6 Gbit/s, and vice versa, though SATA 1.5 Gbit/s devices only connect with SATA 6 Gbit/s devices at the slower 1.5 Gbit/s speed.

text: Comparison to other interfaces[edit]

text: SATA and SCSI[edit]

text: Parallel SCSI uses a more complex bus than SATA, usually resulting in higher manufacturing costs. SCSI buses also allow connection of several drives on one shared channel, whereas SATA allows one drive per channel, unless using a port multiplier. Serial Attached SCSI uses the same physical interconnects as SATA, and most SAS HBAs also support 3 and 6 Gbit/s SATA devices (an HBA requires support for Serial ATA Tunneling Protocol).

text: SATA 3 Gbit/s theoretically offers a maximum bandwidth of 300 MB/s per device, which is only slightly lower than the rated speed for SCSI Ultra 320 with a maximum of 320 MB/s total for all devices on a bus.[68] SCSI drives provide greater sustained throughput than multiple SATA drives connected via a simple (i.e., command-based) port multiplier because of disconnect-reconnect and aggregating performance.[69] In general, SATA devices link compatibly to SAS enclosures and adapters, whereas SCSI devices cannot be directly connected to a SATA bus.

text: SCSI, SAS, and fibre-channel (FC) drives are more expensive than SATA, so they are used in servers and disk arrays where the better performance justifies the additional cost. Inexpensive ATA and SATA drives evolved in the home-computer market, hence there is a view that they are less reliable. As those two worlds overlapped, the subject of reliability became somewhat controversial. Note that, in general, the failure rate of a disk drive is related to the quality of its heads, platters and supporting manufacturing processes, not to its interface.

text: Use of serial ATA in the business market increased from 22% in 2006 to 28% in 2008.[70]

text: Comparison with other buses[edit]

text: SCSI-3 devices with SCA-2 connectors are designed for hot swapping. Many server and RAID systems provide hardware support for transparent hot swapping. The designers of the SCSI standard prior to SCA-2 connectors did not target hot swapping, but in practice, most RAID implementations support hot swapping of hard disks.

text:
Name
Raw data rate
Data rate
Max. cable length
Power provided
Devices per channel

eSATA
6 Gbit/s
600 MB/s

2 m
1 m with passive SATA adapter

No
1 (15 with a port multiplier)

eSATAp
6 Gbit/s
600 MB/s
5 V, and, optionally, 12 V[71]

SATA revision 3.2
16 Gbit/s
1.97 GB/s[e]
1 m
No

SATA revision 3.0
6 Gbit/s
600 MB/s[72]

SATA revision 2.0
3 Gbit/s
300 MB/s

SATA revision 1.0
1.5 Gbit/s
150 MB/s[73]
1

PATA (IDE) 133
1.064 Gbit/s
133.3 MB/s[f]
0.46 m (18 in)
5 V (only 2.5-inch drive 44-pin connector)
2

SAS-3
12 Gbit/s
1.2 GB/s
10 m
Backplane connectors only
1 (> 65k with expanders)

SAS-2
6 Gbit/s
600 MB/s

SAS-1
3 Gbit/s
300 MB/s

IEEE 1394 (FireWire) 3200
3.144 Gbit/s
393 MB/s
100 m (more with special cables)
15 W, 12–25 V
63 (with a hub)

IEEE 1394 (FireWire) 800
786 Mbit/s
98.25 MB/s
100 m[74]

IEEE 1394 (FireWire) 400
393 Mbit/s
49.13 MB/s
4.5 m[74][75]

USB 3.1 (Generation 2)
10 Gbit/s
1.21 GB/s[g]
3 m[76]
100 W, 5, 12 or 20 V[77]
127 (with a hub)[76]

USB 3.0[h] (USB 3.1, Generation 1)
5 Gbit/s
400 MB/s or more (excl. protocol
overhead, flow control, and framing)[78]
4.5 W, 5 V

USB 2.0
480 Mbit/s
35 MB/s
5 m[79]
2.5 W, 5 V

USB 1.1
12 Mbit/s
1.5 MB/s
3 m
Yes

SCSI Ultra-320
2.56 Gbit/s
320 MB/s
12 m
Backplane connector only
15 excl. host bus adapter/host

10GFC Fibre Channel
10.52 Gbit/s
1.195 GB/s
2 m – 50 km
No
126 (16,777,216 with switches)

4GFC Fibre Channel
4.25 Gbit/s
398 MB/s
12 m

InfiniBand
Quad Rate
10 Gbit/s
0.98 GB/s

5 m (copper)[80][81]
<10 km (fiber)

1 with point-to-point, many with switched fabric

Thunderbolt
1.22 GB/s

3 m (copper)
100 m (fiber)

10 W (only copper)
7

Thunderbolt 2
20 Gbit/s
2.44 GB/s

Thunderbolt 3
40 Gbit/s
4.88 GB/s
100 W (only copper)