I’m at a loss. And I believe to have narrowed it down to an issue with the GPU. But I wanted to ask and see if anyone else had an idea for diagnosis.
I have a 5700 XT. I had the HDMI and all 3 DP ports populated going to 3 1080P monitors and a 1080P TV. As none of my monitors had a Display Port, I used DP to HDMI converter cables to accomplish this.
One day DP 3 stopped working at 1080 P and would only output in 800x600. I also noticed that my OS wouldn’t show the name of the device any longer (other outputs would show Sony 1080 P, for example). This would only show a generic “DP-3 800x600”
A few days later, the same fate befell DP-2. And the same for DP-1 shortly after.
I figured at the time this was an issue caused by tinkering with my Arch OS. I booted into Windows to verify or rule out that possibility. In Win10, the 800x600 displays did not show as a display option at all.
I remember that my cables seemed a little warm to the touch at their ends. I’d purchased all 3 DP to HDMI cables at the same time. Figuring they were simply bad, I ordered a new set from a different brand. No luck. Brand new cables did the same thing.
The standard HDMI to HDMI still outputted in 1080P
I updated/reinstalled the 5700XT bios and the MSI x470 Plus firmware. This did not resolve the issue either.
At this time, my WFH job happened to send me a couple cheap HP monitors. And they happened to have Display Port inputs on them.
I connected those to the GPU, and viola, 1080P from all 3 Display Port outputs over a standard DP to DP cable! So the 5700xt does still work on all ports.
Using the DP to HDMI cables (new and old) connecting to the same HP monitors I just received, however, would still only output in 800x600.
I’ve also tried vfio passthrough of the 5700xt to various VMs, same issue on all of those.
As long as a DP to HDMI conversion cable is connected to any of the 3 DP outputs on the 5700XT, it will now only output in 800x600.
So I believe I have done enough experimenting to confirm it’s not an OS issue, and therefore not a driver issue.
This happens on all 6 different model monitors I’ve had access to to try.
This happens on all 3 PCIe slots, with or without a riser cable.
All DP ports are verified to work when using a regular DP cable.
I’ve recently upgraded to a 1000W Seasonic PSU - no change.
The only thing I haven’t been able to try is putting this card on a different motherboard with a different CPU.
I find it especially odd that it used to work, and the issue came up one port at a time.
Have I missed anything? Does anyone have a clue what could be the issue? Does it seem reasonable my 5700XT is just having a bad time?