New PC restars when playing games but can't pinpoint what's wrong.

[xxB4N4]

I built this PC a week ago and have had this problem since day 1 where the screen flickers and after a while it reboots, but sometimes it doesn't flicker before rebooting. I've looked at the psu, gpu temps, cpu temps, switched RAM slots, reinstalled drivers, reinstalled windows, updated BIOS, etc and nothing worked. I tried running games in windowed mode but it barely makes a difference. One thing that i've been looking at today is my RAM memory frequency thingy in BIOS and it's only at half of advertised speed. I looked it up and it says to enable XMP but there isn't an option for XMP, only DOCP. I tried enabling DOCP in the hopes that it would fix the reboot issue but when I saved the changes and restarted I got an american megatrends screen and it said something about POST and that I need to go into BIOS and reset the changes I made(enabling DOCP). After reseting the AI overclock tuner to auto it goes back to running normally(with the exception of rebooting when running games). Since day 1 it also says that the VGA card is not supported by this UEFI and I tried updating the VGA drivers but to no avail, but I use HDMI so it shouldn't matter(?). I'm also gonna be trying a different gpu to see if that is the problem. Also I know barely anything about computers so i've just been following instructions on what measures to take and nothing have worked, PLEASE HELP ME!!

 

My specs:

CPU-Ryzen 7 3700x

Cooler-Wraith prism RGB cooler

Motherboard-Asus rog strix b550-f

GPU-Sapphire Nitro+ rx 580 4GB(bought used cus no GPUS)

RAM-HyperX fury DDR4 2x16GB 3600mhz RAM

SSD-Kingston A2000 M.2 500GB

PSU-Corsair CX750F RGB

 

 

[SupaKomputa]

You can diagnose the problem by monitoring the temp for the cpu and gpu.

You can open the radeon software or msi afterburner.

CPU & GPU Temp should not be over 90c.

[xxB4N4]

1 minute ago, SupaKomputa said:

You can diagnose the problem by monitoring the temp for the cpu and gpu.

You can open the radeon software or msi afterburner.

CPU & GPU Temp should not be over 90c.

yeah i've done that and neither component is overheating. I use the radeon software.

[SupaKomputa]

In radeon performance setting, drag the gpu mhz -10%

[xxB4N4]

9 minutes ago, SupaKomputa said:

In radeon performance setting, drag the gpu mhz -10%

alright I did that. Gonna check if it makes any difference.

 

[xxB4N4]

21 hours ago, SupaKomputa said:

In radeon performance setting, drag the gpu mhz -10%

It did not make any difference.