{{Short description|Standard for miniature computer expansion cards}} {{Other uses|M2 (disambiguation){{!}}M2}} {{Redirect-distinguish|NGFF|NGSFF}} {{Use dmy dates|date=August 2014}} {{Infobox computer hardware | name = M.2 | image = 250px | caption = An M.2 2280 solid-state drive (SSD), 22 mm wide and 80 mm long with the key in the M position | invent-date = | invent-name = | designfirm = PCI-SIG | introduced = {{Start date and age|2013|11|01}} | discontinued = | conn1 = Motherboard | via1_1 = PCIe 2.0 ×4 | via1_2 = PCIe 3.0 ×4 | via1_3 = PCIe 4.0 ×4 | via1_4 = PCIe 5.0 ×4 | via1_5 = Serial ATA 3.0 | via1_6 = USB 3.0 | via1_7 = | class-name = Speeds | class1 = | class2 = | class3 = | class4 = | class5 = | manuf1 = Intel | manuf2 = Phison | manuf3 = Realtek | manuf4 = Sandisk | manuf5 = Samsung | manuf6 = Silicon Motion | manuf7 = SK Hynix | dimensions = {{ubl | Width: {{cvt|22|mm}} | Lengths: {{cvt|30|,|42|,|60|,|80|or|110|mm}} }} }} thumb|250px|A size comparison of an mSATA SSD (left) and an M.2 2242 SSD (right)
'''M.2''' (pronounced "em-dot-too"),<ref>{{cite web |last=Gillis |first=Alexander S. |date=July 2021 |title=Definition: M.2 SSD |url=https://www.techtarget.com/searchstorage/definition/M2-SSD |website=TechTarget |access-date=February 24, 2022}}</ref> formerly known as the '''Next Generation Form Factor''' ('''NGFF'''), is a specification for internally mounted computer expansion cards and connectors. It was developed to replace the older Mini SATA (mSATA) and Mini PCIe (mPCIe) standards.
M.2 supports a variety of module sizes and interface types, offering greater flexibility for modern devices. It is widely used in compact systems such as ultrabooks and tablet computers, particularly for solid-state drives (SSDs), due to its smaller size and higher performance compared to mSATA.<ref name="snia-webcast">{{cite web |last1=Handy |first1=Jim |last2=Tanguy |first2=Jon |last3=May |first3=Jaren |last4=Akerson |first4=David |last5=Kim |first5=Eden |last6=Coughlin |first6=Tom |date=September 20, 2014 |title=SNIA Webcast: All About M.2 SSDs |url=http://snia.org/sites/default/files/SSSI%20M%202%20Webcast%20Slides%20v10fnl.pdf |website=SNIA |language=en-US |access-date=July 15, 2015}}</ref><ref name="sata-io-m.2">{{cite web |title=SATA M.2 Card |url=https://www.sata-io.org/sata-m2-card |website=SATA-IO |access-date=September 14, 2013}}</ref><ref name="compreviews">{{cite web |last=Kyrnin |first=Mark |title=What Is M.2? New Interface and Form Factor For Compact SSD Drives in Laptops and Desktops |url=http://compreviews.about.com/od/storage/fl/What-Is-M2.htm |website=compreviews.about.com |language=en-US |access-date=July 15, 2015 |archive-date=15 July 2015 |archive-url=https://web.archive.org/web/20150715163843/http://compreviews.about.com/od/storage/fl/What-Is-M2.htm |url-status=dead }}</ref>
The M.2 connector can provide multiple interface options, including up to four lanes of PCI Express, as well as Serial ATA 3.0 and USB 3.0. The supported interfaces vary depending on the device and host implementation. M.2 modules and slots use different "keying" notches to indicate supported interfaces and to prevent incompatible installations.<ref name="snia-webcast" /><ref name="sata-io-m.2" /><ref name="m.2-intro-orvem">{{cite web |title=M.2 Connector (NGFF) Introduction |url=http://www.orvem.eu/attachments/article/130/M%202%20introduction.pdf |url-status=dead |archive-url=https://web.archive.org/web/20140203000954/http://www.orvem.eu/attachments/article/130/M%202%20introduction.pdf |archive-date=February 3, 2014 |website=ATTEND |access-date=January 17, 2014}}</ref>
For storage devices, M.2 supports both the older Advanced Host Controller Interface (AHCI) and the newer NVM Express (NVMe) protocols. AHCI provides compatibility with legacy SATA-based systems and operating systems, while NVMe is designed for high-speed SSDs and allows for much faster performance by supporting multiple simultaneous I/O operations.<ref name="snia-webcast" />{{rp|14}}<ref name="ahci-nvme">{{cite web |last=Landsman |first=Dave |date=August 9, 2013 |title=AHCI and NVMe as Interfaces for SATA Express Devices – Overview |url=https://www.sata-io.org/sites/default/files/documents/NVMe%20and%20AHCI%20as%20SATA%20Express%20Interface%20Options%20-%20Whitepaper_.pdf |website=SATA-IO |language=en-US |access-date=July 15, 2015}}</ref>
== Features == [[File:SATA Express interface.svg|thumb|upright=1.2|
High-level software architecture for SATA Express (also used by M.2),<ref name="snia-webcast" />{{rp|14}} supporting SATA and PCIe devices via AHCI or NVMe.<ref name="ahci-nvme" />{{rp|4}}]]
M.2 modules can integrate multiple functions, including the following device classes: Wi-Fi, Bluetooth, satellite navigation, near-field communication (NFC), digital radio, WiGig, wireless WAN (WWAN), and solid-state drives (SSDs).<ref>{{cite web |title=SATA-IO FAQ: What is the M.2 card and what is the status of the specification? |url=https://www.sata-io.org/sites/default/files/images/SATA-IO%20FAQ%20-%20071813a%20%283%29.pdf#page=2 |website=SATA-IO |date=August 8, 2013 |access-date=July 15, 2015 |format=PDF |page=2}}</ref> The SATA revision 3.2 specification, in its gold revision {{As of|2013|8|lc=yes}}, standardizes M.2 as a new format for storage devices and specifies its hardware layout.<ref name="snia-webcast" />{{rp|12}}<ref>{{cite web |title=Serial ATA Revision 3.2 (Gold Revision) |url=http://www.knowledgetek.com/graphicsNew/SerialATA_Revision_3_2_Gold%28with%20Links%29.pdf#page=194 |archive-url=https://web.archive.org/web/20140327221409/http://www.knowledgetek.com/graphicsNew/SerialATA_Revision_3_2_Gold%28with%20Links%29.pdf |archive-date=March 27, 2014 |format=PDF |pages=194–209 |website=KnowledgeTek |publisher=SATA-IO |date=August 7, 2013 |access-date=July 15, 2015}}</ref> Buses exposed through the M.2 connector include PCI Express (PCIe) 3.0 and newer, Serial ATA (SATA) 3.0 and USB 3.0; all these standards are backward compatible.
The M.2 specification provides up to four PCI Express lanes and one logical SATA 3.0 (6 Gbit/s) port, and exposes them through the same connector so both PCI Express and SATA storage devices may exist in the form of M.2 modules. Exposed PCI Express lanes provide a pure PCI Express connection between the host and storage device, with no additional layers of bus abstraction.<ref name="pcie-storage">{{cite web |last=Wassenberg |first=Paul |date=June 19, 2013 |title=SATA Express: PCIe Client Storage |url=https://www.sata-io.org/sites/default/files/documents/SATA_Express-SV2013.pdf |publisher=SATA-IO |access-date=October 2, 2013}}</ref> PCI-SIG M.2 specification, in its revision 1.0 {{As of|2013|12|lc=yes}}, provides detailed M.2 specifications.<ref name="snia-webcast" />{{rp|12}}<ref name="m.2_specification">{{cite web |title=PCI Express M.2 Specification Revision 1.0 |url=http://www.pcisig.com/specifications/pciexpress/M.2_Specification/ |website=PCI-SIG |year=2013 |access-date=December 14, 2013}}</ref>
=== Storage interfaces === Three options are available for the logical device interfaces and command sets used for interfacing with M.2 storage devices, which may be used depending on the type of M.2 storage device and available operating system support:<ref name="snia-webcast" />{{rp|14}}<ref name="ahci-nvme" /><ref name="pcie-storage" />
; Legacy SATA: Used for SATA SSDs, and interfaced through the AHCI driver and legacy SATA 3.0 (6 Gbit/s) port exposed through the M.2 connector.
; PCI Express using AHCI: Used for PCI Express SSDs and interfaced through the AHCI driver and provided PCI Express lanes, providing backward compatibility with widespread SATA support in operating systems at the cost of lower performance. AHCI was developed when the purpose of a host bus adapter (HBA) in a system was to connect the CPU/memory subsystem with a much slower storage subsystem based on rotating magnetic media; as a result, AHCI has some inherent inefficiencies when applied to SSD devices, which behave much more like RAM than like spinning media.
; PCI Express using NVMe: Used for PCI Express SSDs and interfaced through the NVMe driver and provided PCI Express lanes, as a high-performance and scalable host controller interface designed and optimized especially for interfacing with PCI Express SSDs. NVMe has been designed from the ground up, capitalizing on the low latency and enhanced parallelism of PCI Express SSDs, and complementing the parallelism of contemporary CPUs, platforms and applications. At a high level, primary advantages of NVMe over AHCI relate to NVMe's ability to exploit parallelism in host hardware and software, based on its design advantages that include data transfers with fewer stages, greater depth of command queues, and more efficient interrupt processing.
== {{Anchor|FORM-FACTORS|KEYING}}Form factors and keying == thumb|upright=1.2|M.2 keying notches in B and M positions, with visible pin offset on each side of the module.<ref name="rog-asus-313352014" /> thumb|upright=1.2|Size examples of M.2 SSDs. The first two digits indicate width, the rest length in millimeters (e.g., 22110 = 22 mm wide × 110 mm long). Not all devices support every size.<ref>{{cite web |title=Which SSD is Compatible with PS5? |date=29 March 2023 |url=https://gamingconsole101.com/ps5/which-ssd-is-compatible-with-ps5/ |publisher=Gaming Console 101 |access-date=2 April 2023}}</ref>
The M.2 standard is based on the mSATA standard, which uses the existing PCI Express Mini Card (Mini PCIe) form factor and connector. M.2 adds the possibility of larger printed circuit boards (PCBs), allowing longer modules and double-sided component population. Consequently, M.2 SSD modules can provide double the storage capacity within the footprint of an mSATA device.<ref name="snia-webcast" />{{rp|20,22–23}}<ref name="compreviews" /><ref>{{cite web |title=M.2 Frequently Asked Questions |url=http://www.kingston.com/en/ssd/s/m2_faq |website=Kingston Technology |language=en-US |access-date=July 15, 2015}}</ref>
M.2 modules are rectangular, with an edge connector on one side and a semicircular mounting hole at the center of the opposite edge. The edge connector has 75 positions with up to 67 pins, employing a 0.5 mm pitch and offsetting the pins on opposing sides of the PCB from each other. Each pin on the connector is rated for up to 50 V and 0.5 A, while the connector itself is specified to endure 60 mating cycles.<ref name="te-ngff" />{{rp|6}} However, many M.2 slots (Socket 1, 2 and 3) found on motherboards only provide up to 3.3 V power.<ref>{{Cite web | url=https://media.digikey.com/pdf/Data%20Sheets/Viking%20PDFs/PSFNP5xxxx5xxx_C.pdf | title=NVMe PCIe SSD - M.2 2280 Manual | website=media.digikey.com}}</ref><ref>{{Cite web | url=https://www.nxp.com/docs/en/application-note/AN13049.pdf | title=AN13049 - Wi-Fi/Bluetooth/802.15.4 M.2 Key E Pinout Definition | website=www.nxp.com}}</ref><ref>{{Cite web| title=Intel Solid-State Drive 530 Series (M.2) | url=https://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/ssd-530-m2-specification.pdf | archive-url=https://web.archive.org/web/20130912015149/http://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/ssd-530-m2-specification.pdf | archive-date=2013-09-12}}</ref>
The M.2 standard allows module widths of 12, 16, 22 and 30 mm, and lengths of 16, 26, 30, 38, 42, 60, 80 and 110 mm. Initial line-up of the commercially available M.2 expansion cards is 22 mm wide, with varying lengths of 30, 42, 60, 80 and 110 mm.<ref name="sata-io-m.2" /><ref name="m.2-intro-orvem" /><ref name="te-ngff" /><ref>{{cite web |last=Mujtaba |first=Hassan |date=July 2, 2013 |title=Intel SSD 530 Series Arriving Next Week – Feature NGFF M.2 Interface |url=http://wccftech.com/intel-ssd-530-series-arriving-august-2013-feature-ngff-m2-interface/ |website=Wccftech |language=en-US |access-date=September 14, 2013}}</ref> The codes for the M.2 module sizes contain both the width and length of a particular module; for example, "2242" as a module code means that the module is 22 mm wide and 42 mm long, while "2280" denotes a module 22 mm wide and 80 mm long.
An M.2 module is installed into a mating connector provided by the host's circuit board, and a single mounting screw secures the module into place. Components may be mounted on either side of the module, with the actual module type limiting how thick the components can be; the maximum allowable thickness of components is 1.5 mm per side, and the thickness of the PCB is {{nowrap|0.8 mm ± 10%}}.<ref name="m.2_specification" /> Different host-side connectors are used for single- and double-sided M.2 modules, providing different amounts of space between the M.2 expansion card and the host's PCB.<ref name="compreviews" /><ref name="m.2-intro-orvem" /><ref name="te-ngff" /> Circuit boards on the hosts are usually designed to accept multiple lengths of M.2 modules, which means that the sockets capable of accepting longer M.2 modules usually also accept shorter ones by providing different positions for the mounting screw.<ref>{{cite web |title=M2P4S M.2 (NGFF) PCIe base SSD to PCIe ×4 Adapter |url=http://www.hwtools.net/Adapter/M2P4S.html |website=HW Tools |language=en-US |date=February 14, 2014 |access-date=June 22, 2014 |archive-date=17 May 2014 |archive-url=https://web.archive.org/web/20140517005426/http://www.hwtools.net/Adapter/M2P4S.html |url-status=dead }}</ref><ref>{{cite web |last=Burek |first=John |date=April 14, 2015 |title=2015 Guide: The Best M.2 Solid-State Drives |url=http://www.computershopper.com/feature/2015-guide-the-best-m.2-solid-state-drives |website=Computer Shopper |language=en-US |access-date=July 15, 2015 |archive-date=28 December 2015 |archive-url=https://web.archive.org/web/20151228055155/http://www.computershopper.com/feature/2015-guide-the-best-m.2-solid-state-drives |url-status=dead }}</ref>
{| class="wikitable" style="margin-left: 0.5em; margin-right: 2em; margin-top: 0.75em; margin-bottom: 0.9em;" |+ M.2 module keying and provided interfaces<ref name="m.2-intro-orvem" />{{rp|8}}<ref name="te-ngff">{{cite web |title=M.2 (NGFF) Quick Reference Guide |url=http://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=1-1773702-1NGFFQRG-EN&DocType=DS&DocLang=EN |format=PDF |website=Tyco Electronics |access-date=November 16, 2013}}</ref>{{rp|3}}<ref>{{cite web |title=SMBus interface for SSD Socket 2 and Socket 3 (PCI-SIG engineering change notice) |url=https://pcisig.com/sites/default/files/specification_documents/4_SMBus_interface_for_SSD_Socket_2_and_Socket_3.pdf#page=5 |format=PDF |page=2 |website=PCI-SIG |date=August 11, 2014 |access-date=August 5, 2015 |archive-url=https://web.archive.org/web/20150714093722/http://pcisig.com/sites/default/files/specification_documents/4_SMBus_interface_for_SSD_Socket_2_and_Socket_3.pdf#page=5 |archive-date=July 14, 2015 |url-status=dead}}</ref><ref>{{Cite web |title=How to distinguish the differences between M.2 cards |url=https://www.dell.com/support/article/en-us/sln301626/how-to-distinguish-the-differences-between-m-2-cards?lang=en |website=Dell |language=en-US |access-date=March 24, 2020}}</ref><ref name="pcisig 2013-11">{{cite web |title=PCI Express M.2 Specification, Revision 1.0 |url=http://read.pudn.com/downloads794/doc/project/3133918/PCIe_M.2_Electromechanical_Spec_Rev1.0_Final_11012013_RS_Clean.pdf#page=23 |archive-url=https://web.archive.org/web/20210118201723/http://read.pudn.com/downloads794/doc/project/3133918/PCIe_M.2_Electromechanical_Spec_Rev1.0_Final_11012013_RS_Clean.pdf#page=23 |archive-date=January 18, 2021 |format=PDF |page=23 |website=PCI-SIG |date=November 1, 2013 |access-date=June 13, 2020}}</ref> |- ! Key<br />ID ! Notched<br />pins ! style="min-width: 27em;" | Provided interfaces ! Dimensions ! Uses |- | style="text-align: center;" | A<br>(Socket 1) | style="text-align: center;" | 8–15 |2 × PCIe ×1, USB 2.0, I<sup>2</sup>C and DP ×4 | 1630, 2230, 3030 | Wi-Fi, WWAN, GPS, Bluetooth, NFC |- | style="text-align: center;" | B<br>(Socket 2) | style="text-align: center;" | 12–19 | SATA, PCIe ×2, USB 2.0 and 3.0, audio, UIM, HSIC, SSIC, I<sup>2</sup>C and SMBus | 2230, 2242, 2260, 2280, 22110 | SSD |- | style="text-align: center;" | C | style="text-align: center;" | 16–23 | rowspan="2" colspan="3" {{N/A|Reserved for future use}} |- | style="text-align: center;" | D | style="text-align: center;" | 20–27 |- | style="text-align: center;" | E<br>(Socket 1) | style="text-align: center;" | 24–31 | 2 × PCIe ×1, USB 2.0, I<sup>2</sup>C, SDIO, UART, PCM and CNVi | 1630, 2230, 3030 | Wi-Fi, WWAN, GPS, Bluetooth, NFC |- | style="text-align: center;" | A+E<br>(Socket 1) | style="text-align: center;" | 8–15 and 24–31 | 2 × PCIe ×1, USB 2.0 and CNVi | 1630, 2230, 3030 | Wi-Fi, WWAN, GPS, Bluetooth, NFC |- | style="text-align: center;" | F | style="text-align: center;" | 28–35 | colspan="3" style="text-align: center" | Future Memory Interface (FMI) |- | style="text-align: center;" | G | style="text-align: center;" | 39–46 | colspan="3" style="text-align: center" | Reserved for custom use (unused in the M.2 specification) |- | style="text-align: center;" | H | style="text-align: center;" | 43–50 | rowspan="4" colspan="3" {{N/A|Reserved for future use}} |- | style="text-align: center;" | J | style="text-align: center;" | 47–54 |- | style="text-align: center;" | K | style="text-align: center;" | 51–58 |- | style="text-align: center;" | L | style="text-align: center;" | 55–62 |- | style="text-align: center;" | M<br>(Socket 3) | style="text-align: center;" | 59–66 | SATA, PCIe ×4, and SMBus | 2230, 2242, 2260, 2280, 22110 | SSD |- | style="text-align: center;" | B+M<br>(Socket 2) | style="text-align: center;" | 12–19 and 59–66 | SATA, PCIe ×2, and SMBus | 2230, 2242, 2260, 2280, 22110 | SSD |}
{| class="wikitable" style="text-align: center; margin-left: 0em; margin-right: 0.5em; margin-top: 0.75em; margin-bottom: 0.9em;" |+ Maximum component thickness on M.2 modules<ref name="m.2-intro-orvem" />{{rp|8}}<ref name="te-ngff" />{{rp|3}} |- ! Type<br />ID ! Top <br />side ! Bottom <br />side |- | S1 || 1.20 mm || {{n/a}} |- | S2 || 1.35 mm || {{n/a}} |- | S3 || 1.50 mm || {{n/a}} |- | D1 || 1.20 mm || 1.35 mm |- | D2 || 1.35 mm || 1.35 mm |- | D3 || 1.50 mm || 1.35 mm |- | D4 || 1.50 mm || 0.70 mm |- | D5 || 1.50 mm || 1.50 mm |}
[[File:M.2 connector on a computer motherboard.jpg|thumb|right|upright=1.6|An M.2 socket on a motherboard, visible in the upper-left portion of the picture. The socket is keyed in the M position and provides two positions for the mounting screw, accepting 2260 and 2280 sizes of M.2 modules.]]
The PCB of an M.2 module provides a 75-position edge connector; depending on the type of module, certain pin positions are removed to present one or more keying notches. Host-side M.2 connectors (sockets) may populate one or more mating key positions, determining the type of modules accepted by the host; {{As of|2014|04|lc=yes}}, host-side connectors are available with only one mating key position populated (either B or M).<ref name="m.2-intro-orvem" /><ref name="te-ngff" /><ref name="rog-asus-313352014">{{cite web |author=Marshall R. |date=April 7, 2014 |title=Buying an M.2 SSD? How to tell which is which? |url=http://rog.asus.com/313352014/labels/guides/buying-an-m-2-ssd-how-to-tell-which-is-which/ |url-status=dead |archive-url=https://web.archive.org/web/20140427211710/http://rog.asus.com/313352014/labels/guides/buying-an-m-2-ssd-how-to-tell-which-is-which/ |archive-date=April 27, 2014 |website=Republic of Gamers |publisher=ASUS |language=en-US |access-date=April 28, 2014}}</ref> Furthermore, M.2 sockets keyed for SATA or two PCI Express lanes (PCIe ×2) are referred to as "socket 2 configuration" or "socket 2", while the sockets keyed for four PCI Express lanes (PCIe ×4) are referred to as "socket 3 configuration" or "socket 3".<ref name="snia-webcast" />{{rp|15}}<ref>{{cite web |last1=Zhang |first1=Jack |last2=Liang |first2=Mark |title=NVM Express Based Solid-State Drives: Crossing the Chasm, Going Mainstream |url=https://intel.lanyonevents.com/sz15/connect/fileDownload/session/9D9F891F2BE30DC4C945F5F5B197F307/SZ15_SSDS001_102_ENGf.pdf |website=Intel |language=en-US |page=39 |date=July 4, 2015 |access-date=August 27, 2015 |archive-date=5 June 2016 |archive-url=https://web.archive.org/web/20160605094938/https://intel.lanyonevents.com/sz15/connect/fileDownload/session/9D9F891F2BE30DC4C945F5F5B197F307/SZ15_SSDS001_102_ENGf.pdf |url-status=dead }}</ref>
For example, M.2 modules with two notches in B and M positions use up to two PCI Express lanes and provide broader compatibility at the same time, while the M.2 modules with only one notch in the M position use up to four PCI Express lanes; both examples may also provide SATA storage devices. Similar keying applies to M.2 modules that utilize provided USB 3.0 connectivity.<ref name="m.2-intro-orvem" /><ref name="rog-asus-313352014" /><ref>{{cite web |last=Tokar |first=Les |date=November 24, 2013 |title=Understanding M.2 NGFF SSD standardization (or the lack of) |url=http://www.thessdreview.com/daily-news/latest-buzz/understanding-m-2-ngff-ssd-standardization/ |website=The SSD Review |language=en-US |access-date=April 28, 2014}}</ref>
Various types of M.2 modules are denoted using the "WWLL-HH-K-K" or "WWLL-HH-K" naming schemes, in which "WW" and "LL" specify the module width and length in millimeters, respectively. The "HH" part specifies, in an encoded form, whether a module is single- or double-sided, and the maximum allowed thickness of mounted components; possible values are listed in the right table above. Module keying is specified by the "K-K" part, in an encoded form using the key IDs from the left table above; it can also be specified as "K" only, if a module has only one keying notch.<ref name="m.2-intro-orvem" /><ref name="te-ngff" />
Beside socketed modules, the M.2 standard also includes the option for having permanently soldered single-sided modules.<ref name="te-ngff" />
{{anchor|M.3|NF1|NGSFF|XFM}}
== Alternative standards == === NGSFF === <!-- This should be expanded into a separate article, but parked here to have a target for incoming redirects like M.3 (computing), Samsung NF1, NGSFF, Next Generation Small Form Factor --> In 2017, Samsung introduced a new form factor called ''Next Generation Small Form Factor'' (NGSFF), also known as NF1 or M.3, which may replace U.2 in server applications.<ref>{{cite web |last1=Hensel |first1=Martin |last2=Graefen |first2=Rainer |date=July 27, 2018 |title=Was sind NF1, M.3 und NGSFF? |url=https://www.storage-insider.de/was-sind-nf1-m3-und-ngsff-a-736403/ |work=StorageInsider |publisher=Vogel Communications Group |language=de |access-date=July 10, 2022 |url-status=live |archive-url=https://web.archive.org/web/20220710160435/https://www.storage-insider.de/was-sind-nf1-m3-und-ngsff-a-736403/ |archive-date=July 10, 2022}}</ref> The NGSFF connector is electrically and dimensionally compatible with M.2 (revision 1.1)'s connector; new functionality is achieved through previously unused (N/C) pins.<ref name="DWang">{{cite web |last1=Wang |first1=David |title=Next Generation Small Form Factor (NGSFF) SSD Proposal |url=https://files.futurememorystorage.com/proceedings/2017/20170810_FC32_Wang.pdf}}</ref> The main changes compared to M.2 are: * The width (or "height") of the SSD is increased from 22 mm to 30.5 mm; the thickness is increased from 3.88 mm to 4.38 mm. These changes allow more NAND chips to be fitted onto an SSD while still fitting inside a rack unit.<ref name="Samsung">{{cite web |title=NF1 SSD | Samsung Semiconductor |url=https://www.samsung.com/semiconductor/ssd/nf1-ssd/ |website=Samsung |url-status=dead |archive-url=https://web.archive.org/web/20201002081759/https://www.samsung.com/semiconductor/ssd/nf1-ssd/ |archive-date=October 2, 2020}}</ref> * New pins for 12 V power. Devices are supposed to mainly use 12 V power instead of the old 3.3 V, which has been made optional.<ref name="Samsung"/> * Ability to run two PCIe ports (each with two lanes) on one NGSFF port.<ref name="DWang"/> * Features for rackmount servers: hotswap support, indicator LEDs, SSD tray (with new screw holes).<ref name="DWang"/>
In 2018, the PCI-SIG issued a warning that NGSFF's new pin usage clashes with the pin usage in the upcoming 1.2 revision of the M.2 standard. The new revision uses some of the previously non-connected (N/C) pins to deliver 1.8 V power and USB 2.0 data on the "M" socket. Samsung has sought to standardize its NGSFF/NF1 through JEDEC, but the process appears to have stalled.<ref>{{cite web |last1=Tallis |first1=Billy |title=PCI-SIG Warns Of Incompatibilities Between M.2 And Samsung's NGSFF/NF1 |url=https://www.anandtech.com/show/13609/pcisig-warns-of-incompatibilities-between-m2-and-samsungs-ngsff |archive-url=https://web.archive.org/web/20181116213420/https://www.anandtech.com/show/13609/pcisig-warns-of-incompatibilities-between-m2-and-samsungs-ngsff |url-status=dead |archive-date=16 November 2018 |website=www.anandtech.com}}</ref>
=== XFM === <!-- Section anchor is used in incoming redirects. This should be expanded into a separate article. --> JEDEC JESD233 is another specification called ''Crossover Flash Memory'' (XFM) for XFM Embedded and Removable Memory Devices (XFMD). It targets to replace the M.2 form factor with a significantly smaller one (also called XT2), so that it can also be designed as an alternative to soldered memory. XFM Express utilizes a NVMe logical interface over a PCI Express physical interface.<ref name="Lee_2021">{{cite web |last=Lee |first=Matthew |date=August 28, 2021 |title=Move over M.2, here comes the XFM memory specification - And it might displace soldered storage, too, with some luck |url=https://www.techspot.com/news/91000-move-over-m2-here-comes-xfm-memory-specification.html |work=TechSpot |language=en-US |access-date=July 10, 2022 |url-status=live |archive-url=https://web.archive.org/web/20220710164145/https://www.techspot.com/news/91000-move-over-m2-here-comes-xfm-memory-specification.html |archive-date=July 10, 2022}}</ref><ref name="Liu_2019">{{cite web |last=Liu |first=Zhiye |date=August 6, 2019 |title=Toshiba Unveils XFMEXPRESS Form Factor for NVMe SSDs |url=https://www.tomshardware.com/news/toshiba-xfmexpress-nvme-ssd,40104.html |website=Tom's Hardware |language=en-US |access-date=July 10, 2022}}</ref> {{clear|left}}
== Gallery == <gallery widths="200px" heights="160px"> M.2 2242 SSD connected into USB 3.0 adapter.jpg|An M.2 2242 SSD connected into a USB 3.0 adapter and connected to a computer Delock USB m.2 NVMe docking station-oblique FS PNr°0912.jpg|A docking station for M.2 modules Delock USB m.2 NVMe docking station-slot FS PNr°0914.jpg|The connection slot of the docking station Samsung 980 PRO PCIe 4.0 NVMe SSD 1TB-top PNr°0915.jpg|M.2 2280 Samsung 980 PRO PCIe 4.0 NVMe SSD with 1 TB of storage capacity M.2 1630 and M.2 2230 WiFi cards side by side.jpg|M.2 2230 (left) and M.2 1630 WiFi cards </gallery>
== See also == {{Portal|Electronics}} * Enterprise and Data Center Standard Form Factor (EDSFF) * List of interface bit rates * NVM Express (NVMe) * {{Section link|Solid-state drive#Configurations}} * U.2
== Notes == {{reflist|group=lower-alpha}}
== References == {{Reflist|30em}}
== External links == {{Commons category|M.2}} * {{Official website|https://www.sata-io.org|Serial ATA International Organization}} (SATA-IO) official website * {{Official website|https://www.pcisig.com|Peripheral Component Interconnect Special Interest Group}} (PCI-SIG) official website * [https://arstechnica.com/gadgets/2015/02/understanding-m-2-the-interface-that-will-speed-up-your-next-ssd Understanding M.2, the interface that will speed up your next SSD], ''Ars Technica'', February 9, 2015, by Andrew Cunningham * [https://lwn.net/Articles/547903 LFCS: Preparing Linux for nonvolatile memory devices], LWN.net, April 19, 2013, by Jonathan Corbet * [https://web.archive.org/web/20140202110152/http://www.snia.org/sites/default/files/SNIASSSIPCIe101WhitePaper1.12013.pdf PCIe SSD 101: An Overview of Standards, Markets and Performance], SNIA, August 2013, archived from the original on February 2, 2014 * [https://www.congatec.com/fileadmin/user_upload/Documents/Application_Notes/AN43_M.2_Pinout_Descriptions_and_Reference_Designs.pdf M.2 Pinout Descriptions and Reference Designs], January 28, 2020, an application note from Congatec * {{US patent|20130294023|Interface card mount}}{{snd}} US patent 20130294023, November 7, 2013, assigned to Raphael Gay
{{Solid-state drive}}
Category:M.2 Category:Computer-related introductions in 2013 Category:Computer connectors Category:Motherboard expansion slot Category:Peripheral Component Interconnect Category:SATA Express Category:Serial ATA Category:USB