DiLinKer SFF-8643 to SFF-8644 Cable, Internal MiniSAS HD to External MiniSAS HD, 60cm, 12 Gb/s SAS

The cable that gets four SAS lanes out of the box: SFF-8643 (internal 36-pin) on one end, SFF-8644 (external 36-pin, with the pull-latch shell) on the other, 60 cm apart. It is what sits between a host HBA and an external JBOD, disk shelf or tape library — and it carries SAS, so this is not the cable for a U.2 NVMe drive no matter how similar the two connectors look.

What separates 8643 from 8644

• Same four lanes, different shell. SFF-8644 is the external variant of MiniSAS HD: same 36 pins and same 12 Gb/s SAS signalling, but with a shielded, latching shell designed to be plugged and unplugged from outside a chassis. The 8643 end is the internal one that goes to the HBA.
• Twelve gigabits per lane, four lanes. That is 48 Gb/s of SAS bandwidth across the cable, and it negotiates down to 6 Gb/s or 3 Gb/s with older expanders and shelves. It is a SAS link end to end — no PCIe, no NVMe, no U.2 drive support.
• Built for repeated mating. The external end has the pull-tab release and the metal shell that the spec requires, so it survives being cycled every time someone swaps a shelf. An internal 8643 plug pushed into service as an external connector is how ports get damaged.
• Shielding matters outdoors. The 8644 shell is shielded to keep 12 Gb/s signalling clean across the cable and through the bulkhead. That is why this is not simply a longer internal cable with a different connector on the end.

Specifications

Compatibility

Works with

• Host HBAs and RAID cards with an internal SFF-8643 port
• External JBODs, disk shelves, tape drives and DAS enclosures with an SFF-8644 port
• SAS and SATA drives behind an expander in the external enclosure
• 12 Gb/s, 6 Gb/s and 3 Gb/s SAS links

Does not work with

• U.2 NVMe drives and NVMe backplanes — this is a SAS cable; the connectors look alike but nothing will enumerate
• Consumer SATA controllers — they have no 8643 port to plug into
• Port-to-port external runs longer than 60 cm; use an external 8644-to-8644 cable for that
• Connecting SAS drives directly: this is a host-to-enclosure cable, not a drive breakout

Typical deployments

• HBA to a 12-bay external shelf. The 8643 end goes on the card inside the host, the 8644 end onto the shelf, and the shelf’s expander handles the drives.
• Workstation with an external SAS tape or LTO drive. A single cable from an internal port to the external unit, no PCIe bracket adapter needed.
• Lab setup moving a JBOD between hosts. The latching external end is made for that kind of handling; unplug at the shelf, leave the card side alone.

Frequently asked questions

Can I use this for a U.2 NVMe drive?

No. SFF-8644 is physically similar to SFF-8643 and both are 36-pin, but this cable carries SAS signalling. An NVMe drive will not enumerate, and no amount of adapter fiddling changes that. For U.2 you need an SFF-8643-to-SFF-8639 cable or a PCIe-to-U.2 cable, both of which we stock.

Is 8644 the same as 8643 with a bigger shell?

Electrically it is the same four-lane SAS interface; mechanically it is a different, shielded, latching connector intended for external use. That is exactly why this cable exists: to cross from the internal port to the external one without a bulkhead adapter.

What speed will I actually get?

Up to 12 Gb/s per lane, so 48 Gb/s across four lanes, but only if the HBA, the cable, the expander and the drives all support it. A 6 Gb/s expander in the shelf brings the whole link down to 6 Gb/s — normal, and not a cable fault.

How long is the run, exactly?

60 cm connector to connector. That is sized for a host with the card near the bulkhead; if the card is at the far end of a deep chassis, measure before ordering, because external SAS cables are not meant to be stretched.

Can I plug two of these together to make 120 cm?

Not usefully — you would need a 8644-to-8644 coupler, and every extra connector costs signal margin at 12 Gb/s. Buy an external 8644-to-8644 cable in the length you need instead.

Which end goes to the host?

SFF-8643 (the plain internal plug) to the card or board, SFF-8644 (the one with the pull latch and metal shell) to the enclosure. The latch end is always the one you reach from outside.

In the box

• 1 × SFF-8643 to SFF-8644 MiniSAS HD cable, 60 cm, 12 Gb/s SAS (SKU B07Q3TFYZT)

Every cable is continuity- and pinout-tested before it ships and carries a 24-month warranty. If a link does not train, send us the controller model and the backplane part number before returning anything — in most cases the cable is the wrong variant for the port, not faulty, and we would rather tell you that up front.

Related

• Need internal SAS fan-out instead? 8643 host to 4x SATA
• SlimSAS x8 to 2x MiniSAS HD, for newer controllers
• All MiniSAS HD cables