Random reboots with new custom PC old graphics

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Windows 10 pro

PSU Corsair RM 650x

MOBO MSI B450 Tomahawk 

RAM Corsair Vengeance Pro 16g 3200mhz

CPU Amd Ryzen 5 3600

GPU Radeon HD 7970

WD Black 2tb

Samsung 250ssd for boot

 

Everything's BRAND NEW except for GPU. The computer boots up and runs normally under normal load but when the GPU is like running and game or even opening the Steam app the PC automatically reboots itself with no BSOD or error message. All drivers are up to date including the bios with a fresh install of Windows and updates. And I no it's not a heating issue because I consistently check the Temps

I ran a bench test on each individual component and the ones that usually reboot my system are Direct X or under little GPU loads even

I tried to separate graphics card and it does the same thing with that one to. It's a very old Radeon HD 2600 Pro but still works just fine BUT I'VE NOTICED THE MORE POWER MY GPU USES THE FASTER THE REBOOT HAPPENS. For example my 7970 reboots my PC faster than my 2600.

Now I did have the 7970 GPU in a older Intel PC a few weeks ago and it worked just fine. Then I built a new AMD
computer a installed the gpu and Bam automatic reboots out of nowhere

Could it possibly be a directX issue?


This is The Benchmark software I use because it can test each individual component. And everything runs flawlessly except for 3dmark