Rendering bug [2.2.0]

[Trusty McLegit]

So this has happened to me twice now, and seems to be random. Sometimes when I open up GZDoom, everything looks like this. When I close GZDoom and relaunch it, it will usually be fine. I'm using a GTX 1070 if that helps. It's new, so I'm really hoping it's not a broken GPU. I've had no issues with this card in any other game, and only happens occasionally with GZDoom

[Rachael]

That really looks to me like an overheated GPU or RAM chips.

[Trusty McLegit]

My GPU is like 40 degrees. Is there any way to tell if my RAM chips are overheating?

[Rachael]

http://www.cpuid.com/softwares/hwmonitor.html
http://openhardwaremonitor.org/

I am all for open source software (which is why I bothered to link both) but in my opinion the CPUID version does a better job and is more reliable - nevertheless, they both do pretty much exactly the same thing.

Anything that can be sensed, is sensed, with these programs.

I don't know if there's a way to temp your GPU's memory except by touching it with your finger, though. Generally, if it's too hot to touch, the clock frequency is too high, or it needs more cooling.

If your RAM chips are cool, they could just be bad. You might have to get a warranty on that board and see if you can get it replaced. A 1070 should be new enough to still be under warranty. Before you do that, though, make sure you update your driver to rule out a driver issue, first.

[Trusty McLegit]

I was using GPUTweakII and my gpu is 40 degrees from idle, which is what is was when I booted up GZDoom. I downloaded CPUID but it doesn't tell me anything about my RAM. Is there any way to test if my RAM or GPU are broken? Like I said, every other game seems to be fine

[Rachael]

Try a benchmark program. 3D mark tends to be pretty decent. Run it at the maximum possible settings - if everything runs okay with that, it may be a driver issue.

[Trusty McLegit]

I just ran 2 different benchmarks, no problems. If it's a driver issue, I should just wait for the next driver update and then I'll be fine?

[Graf Zahl]

If this happens again, please go to the Display options/OpenGL options/Preferences menu and play around with the options below the bottommost slider and see if some of them triggers this problem. This almost looks like the edges from multsampled antialiasing are being badly processed. So it could be a hardware defect or a driver bug. In any case I suggest to give this image to NVidia as well, maybe they can tell you something more.

[Trusty McLegit]

I was able to get it to do that again, and turning multisampling off and on again fixed it. This time it was only the bottom of the screen though, not the whole screen. What does that mean?

[Rachael]

The only thing that it means is something isn't working as expected. The ambiguity of that is what makes tracking issues like these so difficult. The GPU (and your computer) is so complex and everything depends on one thing or another to work - so when one thing breaks down it can cause odd failures, seemingly intermittent, but it's never easy to say exactly what.

I still suspect bad GPU RAM, especially if it's only affecting portions of the screen. Unfortunately I don't know of many programs that can actually test it.

But please - upgrade your GPU drivers as well - at the very least, to rule that out.

[Trusty McLegit]

My drivers are up to date

[Trusty McLegit]

I also tried out GpuMemTest, and it said there were no issues, though I'm not sure how accurate that program is. In any case, I emailed nvidea so we'll see what they have to say.

[Rachael]

Try one of the programs on here: https://www.raymond.cc/blog/having-prob ... ts-memory/

Little disclaimer: I've never used any of these programs before, so I don't know how any of them work. I'm hoping they'll lead to something conclusive about what's going on with your GPU, though.

If it's not your memory, it could also be your GPU processors, as well, although if it were I think the problems would be much more obvious and less intermittent because you should be seeing rendering errors a lot more frequently if that were the case (or so I would think).

[Graf Zahl]

I don't think it's the RAM. The glitch does not look like random corruption but that the multisampling downfiltering occasionally does not work. My suspicion would be a defective hardware component. And as I said, best report this to NVidia, this is something we cannot help you with here because it's definitely a hardware or driver problem, depending on how this is implemented.