Following up on my graphics card issues, I bought an MSI Geforce GTX 1660 card, deleted a couple of files which were the X AMD drivers (very difficult to delete the packages; seemed to want to delete most of my X system), and loaded the proprietary nvidia driver from the non-free repository.  Nouveau did not seem to work.  Had to add contrib, but it worked like a charm in beowulf.  Took maybe an hour vs the days I struggled with the older AMD card!
It did not work under ascii.  The newest nvidia driver there is 390, and it took 418 to make this thing work under beowulf.  Works fine, 4K video flawless, and only draws 10W normally.
Amazon refused to take back the AMD card because I was a couple of days beyond the 30 day limit.  They said they would, but never sent me the RMA email they promised, and then were uncontactable.  If I ever buy another AMD card, I'll be sure to have time to do all the configuration in two weeks so I can send it back.
--Tim

    On Thursday, February 6, 2020, 6:20:08 PM EST, Tim Wallace via Dng <dng@???> wrote:  

Hi Roland--
I do think that you know the most about the issues with this card...but remember, when I run mpv to display 4K video at 60fps, *full screen* it works perfectly, and does not drop a single frame.  I assume we're bypassing the Xorg software here.  Under X, things just do not work as well.  But the correct advice is to dispense with this card.  It seems like a nice idea to use a workstation card for 10-bit color support and save energy, but using a gamer card shouldn't kill you power-wise if you're not gaming.  Plus some of the RX 560/570 or Nvidia 1050/1060 cards seem able to drive a couple of 4K monitors, if necessary.  I do have a 750W PS so no trouble there but not interested in burning much of that...

--Tim

    On Thursday, February 6, 2020, 9:25:54 AM UTC, Roland Gebhard Sidler <rgsidler@???> wrote:  

Hi Andreas, Tim, Didier,... @Tim: it's definitely not the radeon driver only, that causes the flickering - I tried the radeon and the amdgpu-drivers separately with the same problem appearing.B.t.w., I am working with the default kernel 4.19 in Devuan Beowulf. I guess, the W4100 as well as the WX4100 reach their limits while displaying a 4k video at 60fps... Thank you for your interest and kind answers! Sincerely  Roland 

Am 5 Feb 2020 20:37:27 +0100 (CET) Von Tim Wallace via Dng <dng@???>:
 Hi Andreas-- I do believe that it can be hardware-related, but only to the video card.  I've been running this computer, the same 4K monitor, and the same displayport cable for three years without any problems, except limited graphics performance due to the built-in Intel graphics!  I've got a pile of displayport cables should I want to switch out one of those, and one other 4K monitor as well. I'm very surprised you can get the Xorg amdgpu driver to work with the amdgpu kernel module.  I guess the newest I've used is 5.4.0 from backports, so conceivably 5.4.7 is different, but keep in mind this is a video card first released in 2015, so rather than newer being better, perhaps newer is less compatible as old cards are (silently?) deprecated in some way! I'm taking steps to return this thing, and considering a more typical gaming card such as an RX 560 or 570 or an Nvidia 1050 or 1060.  I don't do gaming, but the video editing should be OK with one of those.  The more I look into the AMD cards, the more people seem to have trouble finding drivers that work well, even on Windows.  I might try them one more time.  It's great to support LInux better than Nvidia does in theory, but in practice ... ?  I also never quite figured out how to run the proprietary AMD drivers under Devuan.  I assume that compiling a kernel which matches the Ubuntu version might do it, but that kind of defeats the purpose of buying a card well-supported in Linux!  Downloading an Nvidia driver is easier than that! Thanks to everybody in DNG who gave me so much good advice, though.  I'm sticking with Devuan no matter what since all my systemd issues are gone! --Tim On Wednesday, February 5, 2020, 6:20:28 PM UTC, Andreas Messer <andi@???> wrote:  Hi Tim,

On Sat, Feb 01, 2020 at 04:44:07PM +0000, Tim Wallace via Dng wrote:
>  Hi Andreas--
> lspci shows this:01:00.0 VGA compatible controller: Advanced Micro
> Devices, Inc. [AMD/ATI] Cape Verde GL [FirePro W4100]which shows the
> Cape Verde but not the Southern Island.  I think all Cape Verde are
> that, though.

Yes, Cap Verde is Southern Island generation. So we basically have the
same card.

> The old radeon kernel module paired with the Xorg radeon driver is the
> one that gives random annoying flashes. I can almost live with them, but
> under virtualbox win7 which my wife runs once a week it is unbelievably
> flashy!

Maybe it is something completely different: At work I had similar issues
with my monitor attached to the notebook dock. From time to time, the
monitor turned black for short time and immediately recovered the image.
It seemed to align with some other employees switching on or off some
devices in the first place, but in the end turned out to be a loosely
fitted display port plug. Could it be the cable? I also heard that in
some cases a bad or insufficient display port cable led to unstable
monitor operation.

It could be also a DP link training issue I do believe that it can be hardware-related, but only to the video card.  I've been running this computer, the same 4K monitor, and the same displayport cable for three years without any problems, except limited graphics performance due to the built-in Intel graphics!
>  The newer amdgpu module fails to work with the Xorg amdgpu driver. 
>  This is with ascii, beowulf, and kernels 4.9, 4.19, and 5.4.  I'm able
>  to get them installed, they just won't start.  The Xorg amdgpu version
>  is 18.1, from late 2018, and a 19.1 is out, from 2019, but claims only
>  minor tweaks.  I'm not thinking it's worth bothering to try to compile
>  that.

Hmm strange. I was using standard beowulf Xorg package with self compiled
kernel 5.4.7's amdgpu module here without any issues.

cheers,

Andreas

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