4x R9700 - Getting Started Ubuntu 24.04 Setup Guide

Wikis & How-to Guides
23

vt-d is not the same as iommu, does ls-iommu still return iommu groups? when iommu is off ls-iommu will not show any output or everything is in one big group

24

It looks like IOMMU was completely disabled, but problem still persists.

autoic@autoic-Default-string:~/ls-iommu$ ./ls-iommu
2026/05/25 18:42:01 IOMMU Disabled in UEFI/BIOS and/or not enabled in boot arguments!

25

waiiiiiit… is this a two cpu system? try a different slot for one of the GPUs. I bet that p2p is blocked if each GPU is on pcie lanes in a different socket.

1 Like
26

I have one CPU with two R9700 installed on PCIe slots 1 and 2. I’ll try another motherboard later this week.

27

Humor me and try export HSA_ENABLE_IPC_MODE_LEGACY=0

1 Like
28

I tried it out, but still getting the same error.

1 Like
29

That got me around the crash using vllm-dev_rocm7.2.3_torch2.11_v0.21.0_20260519, but then hit shared memory broadcast. It uses kernel dmabufs rather than kernel fusion driver.

30

I switched to the X399 platform, and the problem went away.

2 Likes
31

OT: I was just about to post up my x399 Tachi build for sale.

Thanks for convincing me to hold onto it.

32

I am late to the party but taking the plunge

WRX90E Sage
Threadripper Pro 9975WX
128GB RDIMM
2, 3, 4? R9700s

Installing Ubuntu 26.04.1 LTS

or do I need to go back to 24.04 - guess we will find out

33

I’m using a slightly older platform, but running 26.04 with the latest mesa, no problems, mostly.

2 Likes
34

I have finally decided to just let Ubuntu install itself in the path of least resistance “along side of windows” for now to learn about ubuntu running on this kind of setup.

So “For AMD GPUs in these workstations, users may need to install the latest Mesa releases via the Kisak-mesa PPA or the Oibaf PPA to ensure compatibility with newer kernels and hardware.”

" Mesa is only relevant for display output or specific ROCm-based AMD GPU tasks."

  • Installation : Add the Kisak-mesa PPA (sudo add-apt-repository ppa:kisak/kisak-mesa ) for stable updates or Oibaf for bleeding-edge support on Ubuntu 24.04+.
  • Compatibility : Ensure a recent Linux kernel (e.g., 6.14+ ) is used, as older versions may lack support for newer Threadripper PRO features or graphics hardware.

— this is what I see for general guidelines on mesa - any comments?

35

I use kisak-mesa and I use mesa because I primarily use llama.cpp with Vulkan because it’s pretty easy to get decent performance with RDNA4. There are alternatives of course. I have not taken the time to really get vllm working, I have had terrible luck with it. I’m sure it is a lot easier if you are using CUDA.