RX470 PC rebooting

[tmunited99]

So i recently got my new RX470 4gb,  but ever since i had it its been mostly issues. The issue that i experience is the computer rebooting when launching any game. At first, i thought it was (and might still be idk) the PSU, as i had only a poor 400W not very high quality one. Recently i got an Evolveo FX 550 as my PSU. same issue. after doing a ton of research, and nearly pulling my hair out, i installed older drivers  (Radeon crimson relive 17.7.1), which somehow made things work. previously i tried underclocking and a lot of other things but nothing worked. Now while things run, its still not perfect. One specific game (Driver: San Francisco) still causes issues, such as stretched, blurry or vibrating and deformed video, and also just now an ENB mod for GTA San andreas made it reboot. Is it my PSU? Is my GPU faulty? Temps are at 50-60 degrees Celsius.