EVGA 670 FTW2 Signature Overclock

[Galatian]

Hey guys,

I'm sorry if this has been posted before, but unlike for CPUs I couldn't find a good guide on how to overclock my GPU here. I started to overclock via the EVGA Precision Tool and pumped the RAM up to 7200 MHz (1800 x 4). Valley Benchmark ran fine without any artifacts and I saw an increase in both the minimal and the maximum FPS. I checked with OCCT for any errors and so far haven't encountered anything. The GPU stayed at 70°C max with fans on Auto, which is barely audible for me. GPUz reports on one windows that my GPU is "constrained" by max voltage. Do I have to increase voltage now, although everything seems to run fine? How can I further check stability?

Thanks for all your input.

 

[Galatian]

I gained +75 MHz on the Core clock but everything above will result so random black screens for a few seconds when I run Valley Benchmark. GPUz shows that I'm voltage limited in the benchmark, but it seems when I try to up the voltage in the EVGA Precision tools the whole overclock will revert back to stock levels. Any thoughts on why this happens? Do I need a different tool? Do I need to "voltage unlock" first somehow and if yes how do I do this?

 

[Galatian]

Nobody responded but I figured it out eventually ;-)

First I used EVGA Precision with a Custom Fan curve (to prevent thermal throttling), a 145% Power Target and a Maximum Voltage off 1.5 mV to figure out a stable Core Offset overclock. For me this was + 90 MHz.
Rinse and repeat with the RAM Speed. I could go as high as + 520 MHz without any problems in Valley Benchmark, but OCCT would give me a few errors when I would let in run overnight. Now I would combine both and see how stable they would be with the normal (read: quiet) fan curve. I had to lower the Core Offset overlook to +52 MHz. Technically I could have stopped here, but I wanted this change to be permanent.

I used GPU-Z to make a dump of my GPU BIOS and edited it with the Kepler BIOS Tweaker. With the Information I already had from tinkering with the EVGA Precision tool I just had to adjust the Maximum Boost Clock, the Memory Clock, the P0-Voltage and the Power Target.

Now my GTX 670 FTW Signature 2 get's over 200 points more in Valley Benchmark. Especially the minimum FPS have increased. 3DMark also sees rather substantial increase in numbers.
So far I could only check with the built in benchmark from Bioshock Infinite, but it also saw a few FPS more. Mind you this is all within the same original fan curve, which was rather quiet to begin with.