PC shuts off under load, suspecting the GPU

[MiNuN]

Windows 10 Pro Version 21H1 (OS Build 19043.1348)
Motherboard: GIGABYTE GA-X58A-UD7
CPU: Intel BX80613i7980X Core i7 980X Extreme Edition
R.A.M.: Patriot Gamer Series 12GB (3 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600
GPU: XFX AMD Radeon R9 295X2
PSU: Corsair HX1200i 1200W

https://imgur.com/a/2ojlu5F
https://outervision.com/b/wOggbk

My PC is quite old and is now consistently shutting off under load (Streaming, Watching Streams or Playing a Video Game), it does not give me much time before it quickly shuts off after starting one of the mentioned loads, for example I can not even finish one death match in Valorant before it shuts off

I am suspecting my GPU is overheating and is causing the shut downs, often when my PC is idling the fan would rev highly at 3000+ RPM

I would like to isolate the problem and stretch out my PC for a few more years, If I can keep the same build that would be great but I am thinking of testing the PSU, Change the GPU, Change the thermal paste for GPU, maybe even for the CPU (No signs of abnormal temperature)

Please let me know what you think, thank you!

[DaveLembke]

Use speedfan or another tool to see what your temps are all reporting for CPU and GPU and then go from there. If the GPU is roasting then you either need to clean it out of dust and may have to apply new thermal compound. Additionally video cards can fail in a way that they are fine under light loads and then under a heavy load they drop dead and then cool and behave again due to a microfracture in a chip that the connection opens when hot. Lets see what the thermals show before moving forward with swapping parts.

[MiNuN]

It turns out to be my GPU, I am using a temp one right now, I am just wondering if repasting my GPU would help at all

[DaveLembke]

Adding new thermal compound or thermal pads will only work if the GPU hasn't already been damaged. If it was just a thermal condition that tripped up the video card without permanent damage it may be able to be cured but if it has permanent damage then its likely to still act up after replacing thermal compound or thermal pads.

[MiNuN]

how would a gpu be permanently damaged?