Question Sudden low FPS across all games

May 6, 2021
I'm having a bit of a problem with my PC.

After setting an overclock for my 970 with afterburner, I was playing some games (Tarkov, specifically) when my pc suddenly turned itself off, just as if the power cord were pulled. It wouldn't turn back on either, until I plugged it out and back into my wall outlet.

Everything booted up fine, but the GPU now downclocks itself when under load, even though the idle clock is still at its default value at 1215MHz. Whenever under load, the core clock now dips to around 600-800Mhz, which severely caps my performance. Due to this, while my benchmark framerates start as normal, they gradually dip to around 30FPS from 60FPS, depending on the benchmark.

I've discovered that my card is no longer drawing power from 6-Pin #1, severely limiting the power it can receive, and causing massive frame rate drops in benchmarking programs.
In GPU-Z, the PerfCap Reason is Pwr, and my temps sit at around 60 degrees C under load, so it shouldn't be thermally throttling itself. GPU usage goes to 100%.

Things I've tried:
Clean reinstall of old Nvidia Drivers (with and without DDU)
Uninstalling and reinstalling MSI afterburner
Setting power management to "Prefer Maximum Performance", "adaptive", and back
Disabling Gsync
Reseating the GPU
Switching the DVI port from motherboard (was using the integrated GPU) to my 970

Things I want to do, but can't right now:
Test the GPU in a separate machine (this would diagnose my problem as GPU or PSU related, but unfortunately, I don't have easy access to another system to test on)

i7 4790K
16GB DDR3 Ram
1TB NVME M.2 SSD running on a PCIE Riser card
First monitor connected via displayport, second via DVI.

UserBenchmark Results: MSI Z97 GAMING 5 (MS-7917) Performance Results - UserBenchmark

I've done some research and there doesn't seem to be a foolproof solution to this, so I'm slightly concerned my GPU may be done for good, but hopefully I can find a solution soon. The whole "computer abruptly turning itself off" thing makes me think some voltage limit was hit momentarily, causing the GPU to cut power due to excess voltage, but as I'm not too familiar to how these things function, I really have no idea.
Thanks all. At this point, I've kind of given up, but I thought I'd try posting here as a last resort.