I have the PowerColor 5700XT Red Devil. I was crashing quickly after getting in a game. Win won't tell me anything so I hopped on Linux, getting the same instability. But there I was able to redirect error messages to the terminal and a log file. I was getting memory access errors. I downclocked my RAM to JEDEC. Ruled out RAM as with my R9 390 I never had mem access errors. That leaves the VRAM. So I downclocked VRAM to 875mhz after downgrading to 19.12.1 in Windows. Ran 3DMARK Time Spy Extreme for about an hour to stress it and the system did not crash. But 3DMARK close out unexpectedly. However I was getting hard system freezes before the change. I had also lowered the max GPU clock down by 100mhz.
I tried many things over the past 4 days on both Win10 and Arch Linux. I also tried switching out cards, using the other PCIe 16x slot, and different cables. It always pointed to an issue with the 5700XT.
I'm continuing to test. I also want to solve this flickering issue. On Linux I had to go 60hz no freesync. On Win10, I'm at 75hz no freesync. I gets worse as the graphical load increases. Many are having success with CRU profile that changes the freesync range. I will do that soon.
Looks like you're on to something.
