Talk:M.2

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To-do list

Latest comment: 1 year ago5 comments3 people in discussion

What is the relation between "gum stick" SSDs used in, for example, MacBook Air — and the NGFF / M.2 SATA SSDs? Dsimic (talk) 14:26, 14 September 2013 (UTC)Reply
"Gum stick" SSDs are proprietary (not standardized like M.2) — Preceding unsigned comment added by 192.55.55.39 (talk) 17:25, 14 July 2015 (UTC) Reply
What kind of interface do they use, both bus-wise and at the logical level? — Dsimic (talk | contribs) 20:51, 14 July 2015 (UTC)Reply
What is a Plus b 102.212.20.142 (talk) 14:23, 21 May 2025 (UTC)Reply
Some images should be provided for an illustration of different M.2 sizes, and/or for a mSATA vs. M.2 comparison. -- Dsimic (talk) 01:45, 18 September 2013 (UTC)Reply

M.2 keying table

Latest comment: 5 years ago2 comments2 people in discussion

The existing table is somewhat helpful but not intuitive, and is basically a copy of a table in figure 3 of the spec.^[1]^: 23 I propose a somewhat more complex table that is far more descriptive.

M.2 Module Keying^[1]^: §3
Key ID	Notched Pins	Primary Interface	Additional Interface Choices	Intended Use^[1]^: §5
M	59–66	PCIe (4 lanes)	SMBus^[2]	Solid-state drives
M	59–66	SATA
B + M	12–19, 59–66	PCIe (2 lanes)
B + M	12–19, 59–66	SATA
B	12–19	SATA
		PCIe (2 lanes)
		PCIe (2 lanes), USB 2.0, UIM^{[note 1]}	2^nd UIM	Wireless WAN or other (especially future) applications
			Audio, GNSS (I²C)
			Audio, HSIC (USB 2.0), IPC
		USB 3.0 or SSIC, USB 2.0, UIM	2^nd UIM
			Audio, GNSS (I²C)
			Audio, HSIC, IPC
A	8–15	2x PCIe^{[note 2]}, USB 2.0	DisplayPort, I²C	Connectivity such as Wi-Fi, Bluetooth, NFC, WiGig, especially for wireless DisplayPort
A + E	8–15, 24–31	2x PCIe^{[note 2]}, USB 2.0	I²C	WiFi, BT, NFC, or other connectivity
E	24–31	2x PCIe^{[note 2]}, SDIO, USB 2.0	I²C, UART, PCM (I²S)	WiFi, BT, NFC, or other connectivity

↑ The specification refers to a 'User Identity Module', whose purpose and operation are application dependant. It does however mandate compatibility with ISO/IEC 7816. Thus colloquial SIM cards are compatible, and some of the documentation refers to SIM explicitly.
1 2 3 2 separate PCIe interfaces, with 1 lane each. Optionally, can be combined into 1 PCIe interface with 2 lanes.

I'll wait for a week or so before changing the article. Vickas54 (talk) 04:28, 31 May 2021 (UTC)Reply

I completely agree. Besides, the whole article is focused on storage, while M.2 is also used for other purposes. There is a good article, discussing all types of M.2 cards here: https://www.dell.com/support/kbdoc/en-us/000144170/how-to-distinguish-the-differences-between-m-2-cards 213.134.65.133 (talk) 10:38, 2 June 2021 (UTC)Reply

References

1 2 3 "PCI Express M.2 Specification, Revision 1.0" (PDF). PCI-SIG. November 1, 2013. Archived from the original (PDF) on June 13, 2020.
↑ "SMBus interface for SSD Socket 2 and Socket 3 (PCI-SIG engineering change notice)" (PDF). PCI-SIG. August 11, 2014. Archived from the original (PDF) on July 14, 2015. Retrieved August 5, 2015.

Screws to secure M.2 cards

Latest comment: 5 years ago1 comment1 person in discussion

I came here looking for information on the screw needed to secure an M.2 card. They are hard to find. Are they metric M3 threaded screws? Is there a standard size? What does the standard require? 174.28.55.191 (talk) 15:30, 5 July 2021 (UTC)Reply

Transfer speed

Latest comment: 6 months ago1 comment1 person in discussion

Shouldn't this article or the NVMe one have an overview of theoretical speeds for each connector/generation? Even if its mostly derived from PCIe x4 bandwidth. — jonas (talk) 19:40, 6 January 2026 (UTC)Reply

[UIM-3] The specification refers to a 'User Identity Module', whose purpose and operation are application dependant. It does however mandate compatibility with ISO/IEC 7816. Thus colloquial SIM cards are compatible, and some of the documentation refers to SIM explicitly.

[combine_PCIe-4] 1 2 3 2 separate PCIe interfaces, with 1 lane each. Optionally, can be combined into 1 PCIe interface with 2 lanes.

[pcisig_2013-11-1] 1 2 3 "PCI Express M.2 Specification, Revision 1.0" (PDF). PCI-SIG. November 1, 2013. Archived from the original (PDF) on June 13, 2020.

[M.2_SMBus-2] "SMBus interface for SSD Socket 2 and Socket 3 (PCI-SIG engineering change notice)" (PDF). PCI-SIG. August 11, 2014. Archived from the original (PDF) on July 14, 2015. Retrieved August 5, 2015.

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This page was redesigned at the edge.

To-do list

M.2 keying table

Screws to secure M.2 cards

Transfer speed