Yesterday I was at a friend with my graphics card who has a similar PC with the difference that he has a ryzen 5600x and an MSI B550-A PRO motherboard. My rx6800 work stably without a crash for 2 hours, in a game that I mostly crash after a few minutes. Perhaps I should buy this motherboard.
Yes, this will most likely solve the problem, but given your 5800x processor, I would recommend a higher-class board on an X chipset. If it doesn't bother you, try checking your 5800x processor with a friend, too. To make sure that the problem is exactly in the motherboard(or in the processor). And you don't have AMD Smart Access Memory enabled? Since it can cause problems with a black screen. Just if you buy a new motherboard and it turns out that your problem will not solve, then the problem is in the processor(
Alternatively, turn on the power supply circuit (high performance. And not (amd ryzen balanced) So that the processor cores do not park during downtime, so that they constantly receive voltage.
I think the motherboard power section is poor. If I do a CPU or GPU stress test it always passes well, but if I do a CPU and GPU stress test at the same time the PC crashes sometimes. This is probably not the fault of the power supply because my friend has the same power supply model but 650W, and I have 750W.
Everything is possible, but to make sure, check your processor on a friend's PC, or just buy another motherboard, and you have a good power supply, perhaps the vrm on the motherboard is overheating, although it is strange that there are no problems only under CPU load. Load everything together and look through the hwinfo64 utility for data on the voltage and temperature of the CPU. And here's another video card, connect it with two different cables from the power supply, there can be a divider for 2 po(8pin) on one power cable. 2 cables should go from the PSU to the GPU(you have). I have 3 cables from the psu to the gpu)
I ordered a MSI MAG B550 TOMAHAWK motherboard, I will test it when it arrives. People think that it is good for ryzen 5800X. Today I tested the game with a detached sound card and game was stable for 2h without crash. It's very strange.
It is really strange, in some cases it helps to simply pull out the RAM and processor and re-install (somewhere the contact is bad) in different ways, the MB driver on the sound card is buggy or the high audio sampling rate is set by default(on an external sound card). It helps someone to simply flash the card with a new version of the BIOS, since in the first revision there are problems that, according to AMD, have already been solved in the latest drivers.
I replaced mobo few days ago, and still the same problem. Yesterday i noticed even bluescreen, and artifacts in dx11 game. I will contact the seller about the warranty.
How do you have a video card connected, 2 cables go to it from the power supply?(take a photo and attach to the message how the wires from the power supply unit go) There should be 2, one cable holds 150 watts, two of course 300 watts. If one connector is connected, there may be problems under load. Just if they take the card under warranty and check it and they do not have a problem, they can return the card to you back. I have an rx6900xt non-interference, 3 8 pin additional power, 3 separate cables come from the power supply (450 watts in total will withstand) But the card consumes less. see the screenshot. You should have 2 cables running. my power supply is as old as a mammoth's poop)))) but he is already reliable for about 10 years +-)
For me, 2 cables were connected on each tested computer. I wrote to them that problems can occur even after a few hours of playing, and are generally quite rare.