I recently replaced my GPU as it died, I had a sapphire rx480 8gb oc nitro+. I've never had this issue with any cards I've owned, only this one. After installing it and getting my drivers straight I launched a game and within 5 minutes, my system restarted itself. This issue persisted through every game i tried to play, so i tried turning down the global wattman settings on my gpu speed from 1405 (default) to 1345. It worked fine for the passed couple weeks, but the issue would occur once every now and again. Now my computer crashes and restarts itself after running any games for more than 10-20 minutes. I tried lowering the gpu setting to 1300, the issue persisted. I've tried to uninstall drivers and reinstall them, I've tried using older drivers as well. I'm not the only one with this issue though, my friend has a XFX rx480, and his system does the same thing. Im not sure if its a XFX card issue with the current drivers but weve both tried using different ones and clean installing them. We have also gone as far as reinstalling windows completely, the issue continues. Ive looked every where and can find no answers on this and I dont know what to do. The rest of my build is Gigabyte GA-970A-D3P | amd Fx 8350 | ripjaw 2x4gb 1866 | Apevia 900w psu - yes im aware my system needs updating lol. My friend has a all new build excluding his gpu - xfx rx480 8gb | GIGABYTE X470 AORUS Gaming 7 WIFI | ryzen 2700x | 2x8gb 3000mhz corsair vengence | apevia warlock 900w and he recently swapped to a thermaltake 80+ gold psu with the same issue. Neither of us overclock our components either. Thank you to anyone who can help.