It was a hardware issue. My replacement is running perfectly.
For some reason, some games are causing my displays (2K primary + 4K secondary) to flicker, then reboot (if it crashes fast enough). If I’m lucky, I can stop the game, then it’ll stop doing that.
Some games I tried that’s causing it:
Cyberpunk 2077
Mass Effect Andromeda
Life Is Strange: True Colors
the only game that didn’t cause that to happen is Mass Effect Legendary Edition.
One other thing to note, I was using MESA from PPAs that are much newer than what ships with Ubuntu, but I recently just switched back to what came with Ubuntu or Pop!_OS (though they don’t seem to be different).
In addition, I was using this PPA when my issue ocurred. Same thing happened when I went back to what came on Ubuntu/Pop!_OS.
Reason why is because I was trying to fix an issue with my displays flickering at display manager or right after login, and sometimes not working, which I fixed by plugging my desktop directly to the wall. When I tried to see what happens when I go back to the way it was, and no issues occurred at boot, I decided to stick with it.
Bad cable maybe? Quick way to test that is get the shortest possible cable so that it might have the smallest potential signal degradation. Wendel’s Sisyphean quest for high quality display cables tells us all not all cables are made equal and the trifecta of monitor, display cable, and gpu can lead to some shenanigans and inconsistencies. (another way to check this is go with non native resolution and non native refresh rates, 4k panel at 1080p with a bad cable might work out) Edit: I should add I have seen graphics cards keel over and lock up systems because of displays getting disconnected. I’ve not seen it in a long time but if theres some sort of inconsistent connection maybe thats causing a lock up, maybe.
Theres also no harm in putting a stopper on your GPU’s boost clock. 6900XT does a goofy boost clock, similar to how the 5900x handles its turbo clocks, if it has room in its power and thermal budget it will just hit screaming high clocks regardless if your GPU or PSU can actually handle it, you can temper that by tinker with the power limit options to something like minus 10%. Worth a try imo, who cares if you lose a couple percentage points off a synthetic benchmark or two.
Due to the crashes during high power use, I’m inclined to suspect the PSU as well. Some of them just can’t handle the power instantly jumping to the moon and shut off as a safety measure. Also make sure you are using a separate power cable for each GPU power connection. Uninterruptible power supplies can also sometime cause issues.
I honestly don’t know. Last time I used an AMD GPU on Linux was a 6850 and the power controls were called PowerTune or something like that.
Your PSU cabling is probably fine. If the PSU is the problem figuring out how to underclock / cap the power limits would probably help. That said try the using the separate cables anyway, it won’t do any harm.
I have troubleshoot the issue, and I’ve isolated to my 6900XT Phantom Gaming D flickering when I increase the limit @ 2660 MHz (max).
Problem now is that I can’t set it to somewhere in the middle.
Edit: I set the power limit to 200W. That seems to have helped. Gonna be testing more games in the meantime.
Edit 2: I double checked the specs of the 6900XT (both stock and Phantom Gaming D), and according to CoreCtrl, the default maximum is 2660MHz, which is higher than reported boost (gonna try to lower that). In addition, the power limit is at 281W (will try to boost that).
Edit 3: Just tried. Power, according to CoreCtrl, didn’t seem to even go above 150W (think it was around 120W).
My new system is now tainted with Windows 11 (I put it on my 1TB 870 QVO and used up 128GB for it). My Linux install is still on my 2TB 980 Pro. If this works out, I’ll just leave Win11 on the host just to update drivers and stuff, and use the Win11 guest for Halo Infinite and Apex.
I just installed & updated my mobo drivers from Gigabyte, AMD chipset, Asrock’s software, Radeon software, etc. Tested Halo Infinite on Windows and my system didn’t freak out (even enabled overclock mode on my 6900XT to draw out the power).
I’m now back on Kubuntu & tested with JEDI: Fallen Order, Cyberpunk 2077 & Resident Evil 2 (remake). So far so good.
It might happen if your computer screen refresh rate is too low. You can reduce or eliminate flicker by increasing the screen refresh rate. A refresh rate of at least 75 hertz generally produces less flicker.
I guess it’s less of a flicker, but more of a “signal” issue. The display would flicker on and off, and would act like back when our phones can negatively affect TVs.
