[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Migrating system from u-sd to nvme memory on arm64's?




On 13/7/23 10:15, Dan Ritter wrote:
M.2 is an interface format, a micro card edge. M.2 has a set of
key cutouts that specify what exact interfaces are allowed to
connect. It can be used to connect PCIe, SATA, or USB devices.

There are enough possibilities that it's best to reference the
wikipedia article:https://en.wikipedia.org/wiki/M.2

M.2 drives can either be SATA SSDs or NVMe SSDs. SATA is exactly
the same electrical interface as you are used to on 2.5 and 3.5
inch disks, with the same 6Gb/s maximum rate. If you have a
spare SATA port, no point in using up the valuable motherboard
M.2 port.

NVMe (non-volatile memory express) is a command protocol running
directly on PCIe and can run at full PCIe 3, 4 or 5 speed, whatever's
supported by the best intersection of the motherboard and the


What you have said is correct, but in the real world most terms are loosely used , especially SSD.

As examples, the Samsung "860 EVO SATA III M.2 SSD 1TB" is SATA, while the "SSD 980 PCIe 3.0 NVMe M.2" is a PCIe device, but both are called M.2 SSD

Unless it says PCIe in the description then it's not going to be your super speed storage device.

With M.2  there are more than two options for payload depending in part on the key positions.

Key A: This key supports modules that provide wireless connectivity such as Wi-Fi and Bluetooth.

Key B: This key is used for modules that support PCIe (Peripheral Component Interconnect Express) and SATA (Serial ATA) interfaces, typically used for solid-state drives (SSDs) and other storage devices.

Key E: This key is specifically designed for modules providing wireless connectivity, including Wi-Fi, Bluetooth, and cellular modules.

Key M: This key supports modules that use the PCIe interface, typically used for high-speed storage devices such as SSDs.



Reply to: