Niche' ROMED4ID-2T PCIE Ports usecase

Hardware Motherboards
1

Hello all together i hope i can get an insight in what iam doing wrong. [image]

I have an ROMED4ID-2T board and an Epyc CPU Rome in it, i have an 1U case and want my GPU to be seated in the “front” since my PCIE Slot7 (Pcie 16x Slot) is occupied by my Mellanox 100Gbe NIC i want to adapt 2 of those SlimSAS (PCIe 4.0 x8) Ports to one PCIe 16x Slot.

AFAIK the Slim Ports 5+6 are linked together by PCIE lanes Pcie G1 0-7, 8-16

so i bought good cables and two of those SlimSAS PCIe gen4 Device Adapter 2* 8i to x16 daughter boards.

so what works and what not, both do 1x8 Mode no problemo but not 16x Mode.

edit

16x
8x8x
4x4x4x4x

Its all there

edit

I tried to interchange the cables but no 16x, i tried every bifurcation mode in the Bios.

Maybe i have to change something else? Has anybody tried something similar.

regards Dom

https://de.aliexpress.com/item/1005005606630142.html?spm=a2g0o.order_list.order_list_main.22.1a045c5f1dVxdh&gatewayAdapt=glo2deu

24G Internal SlimSAS SFF-8654 to SFF-8654 8i cable, Straight to Left Exit, SAS 4.0, 1-m, 100ohm

2

The outcome interests me as well.

Does the BIOS offer the option to set 16x mode for SlimSAS 5/6 or does it only offer 8x8 or 4x4x4x4?

3

Yes

16x
8x8x
4x4x4x4x

Its all there :slight_smile:

Same goes for Port 1 and 2

And

2 and 3

4

Hmm so if I understand the diagrams/description correctly the connection from SlIMSAS5 should go to the connector near the power plug (1st connector on board) and SLIMSAS6 should go to 2nd connector on board.

What happens? Is it still recognized as x8 or not recongnized at all?

5

still 8x, i always do a full reboot and check with lspci -vvvn -s 45:00.0 | grep LnkSta

45:00.0 is my Nic ID

6

c-payne card are only a cable extender for a pci slot. if you have a pci double slot or thicker, you plug a dongle and then you feed that card with 1 or 2 cable. no bifurcation stuff, it’s only a direct wire extender.

7

I gues thats fine i refer to this bios Setting here

IMG_0341
IMG_03414284×5712 8.13 MB

and that diagram from the Manual

Screenshot 2024-01-31 174855
Screenshot 2024-01-31 1748551551×1039 188 KB

8

Just wondering. DId you hear anything back from Asrock Rack support?

9

Dear Sir,

Thank you for contacting ASRock Rack support.

Sorry but I do not have experience with this type of card. Even so the ports will remain at x8. Maybe one of the ports take precedence ?

Regards,

ASRockRack TSD