Hi,
 
I had bought my EVGA XC Black Edition RTX 2080 TI about 9 months ago and it was working fine up until a couple months ago when I would have problems crashing in games like Apex Legends it would just go completely black screen and I'd have to power off my computer via power button. I did some benchmarking on Unigine Heaven and got abysmally low scores ~2500 on average and was checking gpu-z during this process. It looks like there is an issue with the power consumption it will start out 252w than immediately drop with the total power draw only being ~115w at 55% tdp with perf cap reason switching between idle and pwr during benchmarking / gaming. The core clock is also swinging wildly up to ~1750 and back down to 1350 during gaming and benchmarking and temps. are only reaching ~64c. Is there some kind of throttling going on?
 
Things I've tried that has NOT worked:
 
Restarting Computer
 
Clearing CMOS
 
Have enabled XMP
 
Uninstalling GEforce experience and all overclocking software (precision x1 and afterburner)
 
Uninstalling nvidia drivers with DDU and reinstalling latest ones all in safemode
 
Switching from 1 8pin power connector that splits into two separate 8 pin connectors.
 
Reseating the graphics card
 
Disabling Xbox Game Bar and Windows gaming mode
 
Changing NVIDIA Power management mode to prefer maximum performance and windows power settings to prefer maximum performance under additional power settings.
 
Specs.
 
Liquid cooled i9 9900k (not overclocked) ~40c during tests / gaming
Liquid cooled RTX 2080 TI EVGA XC Black Edition connected via riser cable (not overclocked) ~63c during tests / gaming
16x2 3200mhz Trident Z Royal (xmp mode enabled)
750w SFX Corsair
Z390 I Aorus Pro Wifi (updated bios to f8c the latest one)
Windows Version 10.0.19041 Build 19041
 
 

Get rid of the riser cable, and connect the card directly to the motherboard to see if that helps fix the issue.

I cracked open my gpu water block (heatkiller iv) because of your comment and found out maybe all the thermal pads aren't making contact with the board/block. I found the majority of the thermal pads stuck to the water block and indentations/markings proof that they were making full contact with the board. However, there were 4-5 pads that didn't come up with the water block when I separated it though making me think maybe the ones still attached to the board itself wasn't making full contact with the water block. I threw on some extra thermal padding I had leftover to double layer the ones that didn't look like they were making full contact (the ones still stuck on the board).
 
Booted up my pc and forgot to plug in the two 8 pin connectors for gpu power. Shut it back down turned off power supply, connected the two 8 pins and powered back on (maybe this was the reason it fixed itself?). Ran Unigine Heaven and HELL YEA! my gpu seems to be working normal again with 100% power draw with ~250w. I also dropped 3c and am sitting at 60c now is that still abnormal?

60c is still high for a liquid cooled card.

Yes.