Great time to be a part of this forum. I’ve had lots of success referencing posts on here so thanks to everyone for their input.
I am having an issue with my WS X570-ACE. I am attempting to split the first two PCIe slots into x8/x8 mode. I have the following hardware:
Ryzen 5 3600 (2x8+x4 is supported according to wiki chip)
Vega 64
Broadcom / LSI SAS2388 HBA card (pcie 3.0 x8)
The issue comes when I place the GPU in the top slot. For whatever reason, when I place the GPU in the top slot, 16 lanes get allocated to my GPU and my HBA reports degraded. Here is lspci output comfirming this:
0b:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Vega 10 XL/XT [Radeon RX Vega 56/64] (rev c1) (prog-if 00 [VGA controller])
LnkSta: Speed 8GT/s, Width x16
0b:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Vega 10 HDMI Audio [Radeon Vega 56/64]
LnkSta: Speed 8GT/s, Width x16
0c:00.0 Serial Attached SCSI controller: Broadcom / LSI SAS2308 PCI-Express Fusion-MPT SAS-2 (rev 05)
LnkSta: Speed 8GT/s, Width x4 (downgraded)
If I switch the order of the cards (HBA in top slot/GPU in 2nd slot), the proper allocation occurs:
09:00.0 Serial Attached SCSI controller: Broadcom / LSI SAS2308 PCI-Express Fusion-MPT SAS-2 (rev 05)
LnkSta: Speed 8GT/s, Width x8
--
0c:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Vega 10 XL/XT [Radeon RX Vega 56/64] (rev c1) (prog-if 00 [VGA controller])
LnkSta: Speed 8GT/s, Width x16
interestingly enough, I have an X570 Taichi that exhibits the same behavior. Has anyone else experienced this?