EN-Labs M.2 NVMe M-Key to SFF-8643 Adapter Expansion Card

M.2 M-Key to SFF-8643 Adapter

This add-on card converts an M.2 M-Key NVMe SSD connection to an SFF-8643 Mini SAS interface. It allows a 2.5 inch U.2 SSD to connect to an M.2 slot using an SFF-8639 to SFF-8643 cable, which is not included. The card supports Intel 750 Series U.2 SSDs and fits M.2 2260 and 2280 form factors. No drivers are required with current operating systems.

PCIe 4.0 Interface Limits

The adapter is compatible with the PCIe 4.0 specification and remains backward compatible with PCIe 3.0. Data transfer speeds reach up to 64 GT/s when installed in a PCIe 4.0 slot, dropping to the 3.0 ceiling in older slots. Bandwidth is therefore bound by the host slot generation and the attached drive's own capabilities. The SFF-8643 connector carries four lanes, so x4 NVMe drives operate at full width while x2 drives leave lanes unused.

Build and Connector Implications

The compact PCB mounts directly into an M.2 slot, securing the drive with the motherboard's standard standoff and screw. An external SFF-8643 Mini SAS port faces the rear bracket, requiring a separate SFF-8639 to SFF-8643 cable to reach a 2.5 inch U.2 drive bay. This layout suits chassis with dedicated U.2 bays but adds cable routing steps compared to a direct M.2 installation.