gtx970gpu
Using 3D Mark 11, I ran the benchmark test. During all the lighting and shading renderings, I was getting an acceptable 50-80 FPS, but during the physics rendering, it was down to a pathetic 3.5 FPS.
 

Not sure what conclusions you can draw from the results, but I believe the physics portion of 3DMark 11 test is CPU-based, not the GPU.
 
http://www.futuremark.com/benchmarks/3dmark11

Physics is CPU intensive so Is your CPU overclocked (if yes then set it to normal for now). What happens when you run a CPU test like the Prime95? Another major thing could be your CPU throttling due to heat or other things so what is your clock according to CPU-Z and temp while stressed? Otherwise it could be a unstable OC.

The important thing now is: when you run Prime95, does CPU-Z say the card is throttleing (like at 1.6Ghz). You probably don't need to wait for the passes as I just wanted to know if it handled stress okay.

I think task manager will also tell you your CPU freq if you want to do that instead.

Can you please check the frequency it's running at in CPU-Z when in stress. It's possible your CPU is throttling in stress for some reason. This could explain your 3.5 score in 3dMark.

There's not a need to mess with the GPU, it's clearly a CPU setting/hardware issue.

Can you goto Control Panel > Power Mangement and set the option to "performance" and in advanced settings maybe even set the CPU never to throttle.

That's my guess. Does it fix your issue?

Well, it is overclocked by .2Ghz but that's not the issue and it's not throttling. Maybe someone else knows more.

GPU temp is fine upto 85C until it gets strange and upto 105C till it breaks. CPU is about the same. You would know if the CPU was idling under stress if it was running at ~1.5.Ghz according to CPU-Z. Windows throttles of downclocks your your CPU to save money and to make it last longer but the feature can be glitchy; However, that's clearly not what's going on because your CPU is running at its normal rate.

bsmegreg
GPU temp is fine upto 85C until it gets strange and upto 105C till it breaks. CPU is about the same. You would know if the CPU was idling under stress if it was running at ~1.5.Ghz according to CPU-Z. Windows throttles of downclocks your your CPU to save money and to make it last longer but the feature can be glitchy; However, that's clearly not what's going on because your CPU is running at its normal rate.

 
Thanks for the explanation. My CPU does throttle down to 1.5 Ghz, but only when not loaded. When I ran Prime95, it stayed at the 3.6Ghz without any kind of drops.
 
In terms of temps, the GPU was at 44, but dropped down to the usual 29-33 degrees C once I restarted the Desktop. These are the standard temperatures my GPU has always idled at.

Scarlet-Tech
Does your cpu constantly stay at 3.7 even when you aren't stressing it? It seems like a background program may be causing your grief right now. Monitor it and make sure it down clocks at idle, while watching cpuz. Turn off performance mode in the power settings just to verify thay it isn't keeping it at max.

Yes, under stress, CPU is constantly under full power, never throttling down.
 
I'm 95% confident my CPU is fine, but my GPU is failing. The card already came with a 2-stroke level of loudness fan, so I'm not too disheartened with returning it because at least the techs would test it, and replace whatever is causing the problem.
 
The fact that my build was functioning perfectly fine for weeks in a row, then suddenly my FPS is completely tank really worries me. I need to find out what standard results are for 3D Mark 11 in the first rendering tests on a 970. Either way, the FPS are low, the temps are low. It looks like the card isn't spooling up to correct levels when needed.
 
I'll test my memory tonight, but if I can't come up with a solution by the end of this weekend, I'm going to RMA.