| Drive Type | Form Factor | Connections | Key Type | Socket Type |
|---|---|---|---|---|
| SATA HDDs | 3.5-inch, 2.5-inch | SATA3 ports | N/A | N/A |
| SATA SSDs | 2.5-inch | SATA3 ports | N/A | N/A |
| mSATA SSDs | Mini-SATA | mSATA ports | B key | B socket |
| M.2 SATA SSDs | M.2 | M.2 SATA ports | B key | B socket |
| M.2 NVMe SSDs | M.2 | M.2 NVMe ports | M key | M socket |
| M.2 SATA/NVMe SSDs | M.2 | M.2 SATA/NVMe ports | B+M key | B+M socket |
| U.2 NVMe SSDs | U.2 | U.2 ports | N/A | N/A |
M.2 NVMe drives cannot be plugged into a M.2 SATA port, and vice versa. M.2 SATA drives and M.2 NVMe drives have different interface protocols and different physical connectors.
An M.2 SATA drive uses the SATA interface protocol and has a different physical connector compared to an M.2 NVMe drive, which uses the NVMe interface protocol and has a different physical connector. M.2 SATA and NVMe drives are not physically or electrically compatible with each other.
In the table above, the Key Type column indicates the type of key (B key or M key) found on the bottom of the drive, while the Socket Type column indicates the type of socket (B socket or M socket) found on the motherboard. The B key and B socket are used for SATA-based devices, while the M key and M socket are used for NVMe-based devices.
there is also a B+M key, which is a combination of both the B key and the M key. The B+M key is used for drives that are compatible with both SATA-based and NVMe-based devices. This allows the drive to be used in either a B socket or an M socket, depending on the available interface protocol.
In other words, if a drive has a B+M key, it can be used in a system with either a B socket or an M socket. However, it's important to note that the drive will only perform at the maximum speed and functionality allowed by the interface protocol and the socket type used.
| Drive Type | Form Factor | Dimensions |
|---|---|---|
| SATA HDDs | 3.5-inch | 101.6 mm x 146.1 mm x 26.1 mm |
| SATA SSDs | 2.5-inch | 100 mm x 69.85 mm x 7 mm |
| mSATA SSDs | Mini-SATA | 50.8 mm x 29.85 mm x 4 mm |
| M.2 SATA SSDs | M.2 | 22 mm x 80 mm x 3.5 mm - 22 mm x 80 mm x 5.5 mm |
| M.2 NVMe SSDs | M.2 | 22 mm x 80 mm x 2.38 mm - 22 mm x 80 mm x 3.58 mm |
| U.2 NVMe SSDs | U.2 | 70.10 mm x 22 mm x 15 mm |