All those server connectors on Altra boards - how to use them?

ALTRAD8UD-1L2T lists 4 SlimSAS (PCIe4.0 x8) and 2 OCuLink (PCIe4.0 x4) connectors.

I am not active in server space so have no idea how to make use of such. The only SAS cables I ever used are SAS->4xSATA cables in my NAS which I used to connect hard drives to old LSI HBA.

Can someone enlighten me? In few sentences per each rather than “external/additional nvme storage” please.


My understanding is they’re just unusual connectors for PCIe lanes. For example you can buy a cable that splits the x8 SlimSAS into 2*U.2.

I bought the “DiliVing SlimSAS 8X to 2*U.2 NVMe Adapter,SFF-8654 74pin to 2*SFF-8639 68pin Cable with Power, 75CM(Broadcom MPN 05-60005-00,CBL-SAST-0953)” and am successfully using a couple of NVMe drives.

As an example of how it’s “just PCIe” there’s even an adapter to convert it to a PCIe slot: SlimSAS PCIe gen4 Device Adapter 2* 8i to x16 – C-Payne PCB Design

Similarly with OCUlink, you can buy cables to convert from OCUlink to U.2:

There’s more information about OCUlink and how it’s essentially a better replacement for Thunderbolt at


For an illustration, here’s one of those U.2 NVMe adapters being installed:

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