All –
I recently updated my (Dell desktop) Ubuntu OS from 18.04 to 22.04 (I should have stopped at 20.04 but was feeling too optimistic because Mario said he was planning on upgrading his setups to 22.04 in the coming months). Unfortunately, the AMD Radeon Pro WX 3200 (Polaris GPU architecture) doesn’t play nice with the default kernel in Ubuntu 22.04. I have workarounds for this which is great but it’s got me thinking about what card I should get to work well out-of-the-box in 22.04 so I can get at least a solid 5 years of stable use out of these rigs. Mario mentioned that he’s successfully tested the Raven Ridge chip series (Vega GPU architecture) with 22.04, but the only card that seems reasonable from that family is the Radeon VII which currently costs about $2200 new and I would very much rather not pay that much (particularly since the card is already 3 years old).
And so I turn to you dear forum users, to get a sense of what the PTB Ubuntu end-user community is working with these days. Is anybody running a Radeon Pro RX 5000 or 6000 series in Ubuntu linux? What version of Ubuntu?
I should add that I’m currently driving a VIEWPixx and using a multiple-display setup (just so the “vpixx” tag makes sense).
Thank you in advance for reading and responding!
So obviously, users of older AMD gpu’s and visual stimulators from VPixx or CRS probbably shouldn’t upgrade to Ubuntu 22.04-LTS right now, to spare them some trouble.
One more comment to prevent people from buying Vega’s en masse: The GPU architecture (= design of the hardware acceleration engines for accelerated drawing/post-processing/compute) likely isn’t what matters for your bug, but the type of display engine that turns pixels into a video signal to drive your display device. There’s various mix and match + some added confusion by marketing, because all these marketing people also need to keep their jobs by inventing new names.
E.g., My AMD “RavenRidge” has a Vega gpu architecture (old school), but a new DCN-1 display engine, and it should likely work fine with a ViewPixx. A “Vega” standalond graphics card to plug into a PCI slot, or the “Vega” gpu chips in some of the expensive iToys, do also have the same Vega gpu architecture as my RavenRidge, but an old-style DCE-12 display engine, similar to the DCE-11.2 display engine of your “Polaris” gpu that makes trouble with your VPixx.
Also, don’t overestimate the gpu performance requirements for your use case. If your old cards work fine, you’ll certainly not need a Radeon VII or anything of similar power. I’d bet even my super-cheap onboard AMD chip would likely be sufficient performance-wise to drive your setup just fine for many standard use cases.
Also, as far as i read, gpu’s are really expensive atm. because of all the supply chain issues due to Covid lockdowns in China, and aftereffects of Covid, and various other reasons…
I would expect older AMD gpu’s to work again perfectly fine for years to come in Ubuntu 22.04, after the bug is diagnosed and fixed. And this is also the only known issue with Polaris on Ubuntu 22.04 so far. But yeah, this would likely be a rather easy issue to solve properly if we had actual sane funding. And that funding problem would be easy to solve if the > 99.5% of our users who only pay lip-service would attempt some logical reasoning or long-term thinking and PI’s would spent those 5 minutes once in their life-time to do the few button clicks needed to support us, for a price that is almost a rounding error in the yearly budgets of the majority of labs. Obviously you did the right and reasonable thing by supporting us, so thank you to you and the other < 0.5% of labs.
-mario
Using AMD Radeon Pro WX 3200. Thanks for the update. I’ll look for a more recent card before going to 22,04; using 20.something with no ill effects apparent. I have a more recent AMD still in the box that we will test after we finish our current experiment and will upgrade if it works on a different machine.
If that’s your conclusion from reading this thread, you’ll need to reread it more carefully.
Edit: 18 hours later, the patch with the bug fix for VPixx and CRS visual stimulators on AMD Polaris is now accepted and will be part of an upcoming Linux release (5.19 ~ 5.20). If things don’t go unexpectedly sideways from there on, it will get back-ported/included into some Ubuntu 22.04-LTS Linux 5.15-LTS kernel upgrade within a few weeks or maybe a month or two. For reference:
https://lists.freedesktop.org/archives/amd-gfx/2022-July/081269.html
The advice for AMD Polaris or Vega gpu owners which use CRS or VPixx stimulators/display devices atm. is simply to refrain from upgrading to Ubuntu 22.04 until I give the “all clear”. See this other thread for reference:
"Dithering" with Ubuntu 22.04 / MD Radeon Pro WX 3200 / ViewPIXX - #16 by mariokleiner?
If you don’t intend to use such a CRS/VPixx device, or you have an older card than Polaris, then the problem won’t exist.
If you want to spend some money, I’d rather ask people to buy our paid support licenses to financially support my work. That is money better spent in the mid to long term than on
replacing hw that is almost certainly still perfectly fine for most jobs:
https://www.psychtoolbox.net/#service
People who take part in our user survey will even get a little discount on that license as a thank you.
-mario
Update 21 July: Linux 5.15.56 has been released minutes ago with the bug fix. This took almost exactly 10 days from fix to release. Now Canonicals kernel team has to release a new Ubuntu Linux 5.15 kernel based on the official Linux 5.15.56 kernel, as a software upgrade for Ubuntu 22.04-LTS, ETA is between days and weeks, but a happy end is basically guaranteed now.
-mario
Hi Mario,
Super this got done so smoothly, I think we’re all glad you have your fingers in that pie too 
And if more than almost zero beneficiaries of this kind of work and a lot of other related work would express their content with this by actually buying paid support memberships from us, to support my work, this might even continue indefinitely. Or not, but that is up to our users, if they actually care about working and trustworthy research equipment.
Update 11th October 2022: Both Ubuntu 20.04.5-LTS with HWE stack, and the current Ubuntu 22.04.1-LTS now have the bug-fixed kernels available as part of their regular software updates. Specifically Ubuntu kernel versions “Ubuntu-5.15.0-50.56” and later are now fixed. So simply triggering a regular software update and a reboot of the machine will fix this problem on AMD Polaris and Vega graphics cards, making devices from VPixx or CRS work fine again.
→ Case closed, with a total time from diagnosis to easy to install bug fix of 3 months.
-mario
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