OCuLink ambiguity

Started by pocock, June 01, 2020, 02:05:08 AM

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pocock


When I look at the ordering pages on the Raptor site, it offers various OCuLink products:


  • 4x OCuLink PCIe Expander (Gen 3)
  • OCuLink to U.2 Cable

The manual:
https://wiki.raptorcs.com/w/images/e/e3/T2P9D01_users_guide_version_1_0.pdf

includes errata stating that

ER0001
μPCIe connector (J10108) is incorrectly identified as OCuLink (SFF-8621) due to errors that were discovered post-production in IBM OpenPOWER reference designs.  While the physical connector is the same as OCuLink ports, the wiring is different, notably in the presence detect / clocking pins.  As such, while an OCuLink peripheral is unlikely to be damaged by being plugged in to the μPCIe port, it will not function while attached.


If that is the case, buyers selecting the OCuLink products will not be able to use them - or has the board design been changed somehow to make OCuLink work?
Debian Developer
https://danielpocock.com

pocock


From the Thunderbolt 3 thread...

Quote from: MPC7500 on June 16, 2020, 07:31:00 PM
The only thing I can say is that a working OCuLink adapter is listed in the RCSwiki.

but it is odd that the ordering page includes an option to select an OCuLink PCIe Expander but the form doesn't include any of the OCuLink adapters.  When I noticed that, it left me wondering if there is OCuLink support on the motherboard.  It would be no use for somebody to order the expander and motherboard without also ordering one of the OCuLink adapter cards.
Debian Developer
https://danielpocock.com