GPU is having cyclic power throttling

[Exxidae]

Today while playing I randomly started getting heavy FPS drops, so I ran diagnostics.

What I figured is that my GPU is getting power throttled in a strange way. It goes up to the clock it's supposed to be, then underclocks down to legit nothing, and it goes back up again, cycling forever.

Here is a video footage of it happening: https://youtu.be/sZ0N-yL6uMM

 

I have no idea why it's doing this, I clean reinstalled my drivers several times with several different versions, I unplugged the PSU, and I can't think of much else.

 

Build: https://pcpartpicker.com/user/qruul/saved/#view=6phV3C

GPU: Gigabyte Geforce GTX 980 Ti G1 Gaming

PSU: EVGA SuperNOVA NEX 650W 80+ Gold

Mobo: Asus Z170 PRO GAMING

[Jurrunio]

Max out the power limit then

[Exxidae]

I have had the following power settings on Gigabyte's OC software (OC Guru) for a while now, it just started doing this.

When I set the GPU Temp as target, it was still doing the same thing.

 

Edit: an extra thing to note:

Around a month ago while gaming, my PC randomly shut down. When I turned it back on, BIOS said that my motherboard's anti power surge was triggered, that's why it turned off. I'm running on an UPS so I found that greatly concerning. After that I couldn't even boot into Windows without safe mode, I was stuck on a black screen.

 

I finally got back into regular Windows after uninstalling my GPU driver, but I just couldn't reinstall it for whatever reason. Messing around, I somehow managed to reinstall my GPU driver, only to go back to having black screens whenever it went up in clocks.

 

I was like meh, my GPU probably died, I'm just going to RMA it. But that power surge thing was still bugging me, so before calling it a day I did a power-cycle on my PSU, unplugging it. Somehow after that my problem got fixed, GPU went back to running as normal, until today.

I'm thinking it might be either my PSU or GPU dying, but I'm not sure, and I'm not able to try it with different parts. It works fine on the integrated GPU, but it barely pulls any power.

 

Edit2: some graphs: