So this problem first started after I did a fresh install of windows a couple weeks ago, migrating to a new boot SSD as well.
Ill be in the middle of a game (Apex legends and Warframe which ive been playing lately) in a scene that doesnt seem particularly intense to render (ie, theres been scenes with a ton of particles or intense graphics and its fine) and my screen will freeze and ill get a windows pop-up in the corner saying 'Default Radeon WattMan settings have been restored due to unexpected system failure'. The game will still be running in the background, i can hear it, clicking will still fire guns and i can walk around, but the display is frozen on an image and theres no way to return, i just have to force quit it and start again.
Ive tried raising my power limit and wiping the drivers and doing a clean install, neither seem to do much, i have no idea whats causing it and i cant recreate scenes which i know will crash it.
I have to imagine its some sort of software problem on my end because everything was working fine before i did a reset of windows.
Raising the power limit slider to it's maximum in Radeon Settings usually fixes this issue. Give it a try and report back if that does not help.
Raising the power limit alone didn't help but, i saw another fix online that has seemed to work so far.
Evening out the clock speeds rather than having them go up incrementally as well as raising the power limit.
I know this will degrade performance but you could underclock the card a bit and that should help too. If it is still under warranty you could try and RMA it.
I don't have that specific card, my Kodi system has the R9 380 from PowerColor. An oldie but goodie, for sure. From the description of the symptoms I would guess the GPU is either under-volted, or there is a power issue. Since you are not overclocking the GPU, we can rule that out. A few simple things to try would be dropping back to an older driver and see if the problem persists. If the problem clears up then it is driver version specific. If the problem persists I would try to decrease the clock speed on the GPU. It may be that the new install of Windows brought over some other updates that are moving things along a bit quicker and the GPU can't cope. A simple decrease of 20 Mhz won't hurt game play that much (if at all) and would suffice as a good test. Also, this could actually be coincidental and something else is happened at the same time the PC was reloaded, and they are unrelated. If you have another PSU on hand, you could try swapping that in and see what results you get. I surely would not go under 600 watts. Perhaps a 700 or 750 watt unit, if one is available. Another thing to try that is totally free is to reseat the power cable to the GPU (and the PSU if it is modular), and the GPU to the motherboard. It wouldn't be the first time reseating a cable and/or card cured some bizarre problem.
Tried everything you suggested besides other PSU because i dont have a spare. I even tried using the GPU the drivers from the asus website for the card rather than Radeon Adrenalin (even though im pretty sure i was using R.A drivers not the one from asus) but it still crashes randomly : (
Ive never had to RMA or deal with warranty before, does it require the original box because i lost that when moving houses and also have no idea how long the warranty was for but the cards about 3.5 years old now
If you don't have the original box I would imagine the GPU wrapped in bubble-wrap really well and placed inside a shipping carton would suffice. As for warranty, I did a quick look on the Asus website for warranty length. According to what I read the Asus R9-390 has a warranty period of 36 months. If your GPU is 3 1/2 years old, that would be approx 42 months old and would be outside the warranty window. You may want to reach out to Asus support to see if they will still warrant or service the GPU. If you are outside the warranty window it might be cheaper to buy something newer on eBay versus have that one serviced.
I might give Asus support a try, as for buying a new GPU, im currently in the process of getting a new high end system and selling this current one for a little more spending money, if i dont have this GPU working its gonna be a huge pain.