Hi Ludovic,hi Tim, actually, I do have the same issues. I am running a Thinkstation P520Cwith a Radeon Firepro W4100 with a 4K Benq PD3200U. I literally spent weeks of searching information about this problem to get rid of the flickering,but without any success. I tried several distributions (Linux Mint, Devuan and actually MXLinux) without any difference. And I also tried the proprietary drivers, which didn't change anything,installing it after the open driver and by installing it as first driver. I even tried various connections (HDMI, DP). The problem appears irregularely and more frequently whilest watching videos.There is a slight difference between watching 4k/30fps and 4k/60fps, wheras 4k/60fpsshows less flickering of the whole screen than 4k/30fps. And after having watched a 4k/60fps video for some seconds,the screen won't flicker at all for several minutes. My guess is a timing problem of the AMD Firepro W4100. Might be, using a  AMD Radeon Pro WX xxxx would change that? Sincerely  Roland 
Am 30 Jan 2020 04:07:58 +0100 (CET) Von "Ludovic Bellière" <belliere.ludovic@???>:
Hello Tim,
First you need to know the chipset name of your card in order to knowit's family. To do that you need to run (or similar):
```lspci | grep VGA```
It's output on my desktop shows:
```01:00.0 VGA compatible controller: Advanced Micro Devices, Inc.[AMD/ATI] Ellesmere [Radeon RX 470/480] (rev ef)```
This tells me that the chipset name of my card is Ellesmere, which isthe POLARIS architecture. A quick look to [RadeonFeature][1] tells methat POLARIS is part of the [Volcanic Islands family][2]. The [gentoowiki][3] might help too. Knowing the family is important, as it tellsyou how to tell the kernel to load the amdgpu driver before radeon.
Because I suspect FirePro W4100 to be quite old, the [archlinuxhowtos][4] might be helpful to you.
That being said, you might prefer installing the [proprietarydrivers][5] if you plan to use a professional card. I suspect takingthat road would come with its own set of problems.
I hope this helps,Ludovic
[1]: https://www.x.org/wiki/RadeonFeature/[2]:https://www.x.org/wiki/RadeonFeature/#decoderringforengineeringvsmarketingnames[3]: https://wiki.gentoo.org/wiki/AMDGPU#Feature_support[4]:https://wiki.archlinux.org/index.php/AMDGPU#Enable_Southern_Islands_.28SI.29_and_Sea_Islands_.28CIK.29_support[5]:https://www.amd.com/en/support/professional-graphics/firepro/firepro-wx100-series/firepro-w4100
On 29/01/20 23:05, Tim Wallace via Dng wrote:> I have been happily running ascii but upgraded from my Intel built-in> graphics to an AMD FirePro W4100 because I do a lot of 4K video editing,> but no game-playing, and thought this 50W card would save energy and> work well with 4K.  There is a nearly identical Nvidia card, but I> decided to support AMD, for easier Linux support, which has not been my> experience!> > The card booted OK under ascii but was using the Radeon Xorg driver> which gave flashing behavior from time to time, typical of a bad video> driver.  I decided to try beowulf to get some newer versions of stuff.> > I installed a generic ascii on my other partition, then did the upgrade,> from an xterm, perhaps not the smartest idea but it worked.  When I ran> synaptic, it added and removed hundreds of packages!  Not exactly> efficient, but I was left with a working system.  The only issue was> that my Samsung M.2 SSD only boots as efi, and install systems don't> seem to realize that, resulting in boot failure or boot install failure,> but I used the rEFInd program to recover everything, and all seems good> with both beowulf and ascii.> > The situation now is that I can't get the correct X video driver> working, which should be the amdgpu one, under either ascii or beowulf.> (Full screen 4K video plays great at 60 fps under mpv, with nothing> dropped and no flashes.)  I did try disabling pretty much all the> acceleration options on the radeon driver, but that did not help with> the flashing.> > Details:> Motherboard ASRock Z97 Extreme6, i7-4790K, 16 GB, latest Bios 2.80> > added non-free repository, and installed firmware.  On boot, both radeon> and amdgpu kernel modules are installed.  When X starts, the radeon> driver is used.  The xorg.conf output by Xorg -configure calls for the> amdgpu driver, but trying to run, get fatal error:> > amdgpu_device_initialize: DRM version is 2.50.0 but this kernel is only> compatible with 3.x.x> > > Under ascii, the radeon driver is called for by Xorg -configure, and the> error when forcing amdgpu is almost the same, except> >    ... DRM version is 2.49.0...> > It seems that there are some incompatibilities built into both ascii and> beowulf when it comes to this card.  I could compile a kernel (which I> used to do all the time in the 90's, and probably haven't done for 10> years) if that would help with the DRM version issue.> > I tried the Ubuntu version of the proprietary driver from AMD, and it> complained about the kernel version.  I could compile a kernel to match> the Ubuntu one, I suppose, and re-try the proprietary driver, if anyone> thinks that would help.  I'm not looking for the fastest performance in> the world, though, just stability!> > Any advice?> > --Tim> > > > _______________________________________________> Dng mailing list> Dng@lists.dyne.org> https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng>