AMD Ryzen IOMMU on B350 Ugliness

[Patrick]

I was upgrading ryzen06 for DemoEval with GPUs. This is one of the B350 based systems.

Using the newest Zesty image dated March 13, which has Kernel 4.10 as a base, I started seeing something odd:



I did not get to take a snapshot of the IOMMU error on this build, but I did narrow that down to being the cause.

I guess that is the difference between something looking like it should work and actually getting into the details.

 

[eva2000]

Bleeding edge = loosing a few hair follicles once in a while

 

[vanfawx]

Do you still get errors like that if you boot the machine with "amd_iommu=off" as part of the kernel command line?

 

[Tode]

BTW, anybody knows of an ATX B350 with 2x PCI-E 16x from the CPU ?
All seem to not wire all the CPU PCI-E lanes to instead wire all the lanes from the chipset.

I understand that choice in a mATX or iATX format. But on a full ATX with room for all lanes to be wired to slots ??

 

[Patrick]

BTW, anybody knows of an ATX B350 with 2x PCI-E 16x from the CPU ?
All seem to not wire all the CPU PCI-E lanes to instead wire all the lanes from the chipset.

I understand that choice in a mATX or iATX format. But on a full ATX with room for all lanes to be wired to slots ??

Unfortunately, we are unlikely to see that happen.

You can run a GPU in PCIe 2.0 slots.

 

[Tode]

Unfortunately, we are unlikely to see that happen.

You can run a GPU in PCIe 2.0 slots.

True.