OCuLink

OCuLink is a cabled PCI Express interface that links drives, backplanes and external devices without a slot. SNIA's SFF-8611, MiniLink 4/8X I/O Cable Assemblies, defines the plug, and SFF-8612, MiniLink 4/8X Shielded Connector, defines the receptacle. Plugs come in 4X and 8X sizes, and an 8X plug can break out to two 4X plugs. Both internal and external cable assemblies are covered. SFF-9402 notes the connector was formerly called Nano-Pitch I/O.

SFF-8611 Rev 1.0 is dated September 19, 2018 and says the connector meets the internal I/O requirements of T10 SAS-4 and OCuLink 1.0. SFF-8612 Rev 1.0 is dated August 8, 2023 and states the same two. SFF-9402 Rev 1.1 gives multi-protocol internal cable pinouts for SAS and PCIe. Supermicro lists OCuLink SFF-8611 x4 to x4 cables such as the 65 cm CBL-SAST-0819, verified with its servers, AOC cards and storage.

A port labeled OCuLink says nothing about lane count, PCIe generation or protocol. Read the board or dock manual for x4 or x8, the generation, and whether the port carries PCIe or SAS. Order cables by connector standard and lane width.

Sources

Last verified October 30, 2026.