Hi, from what I know, GPU Tweak is supposed to work with Nvidia cards and AMD. All basic settings may be available when used with EVGA 780Ti SC like GPU clock, memory clock, voltage, fan speed , power target and temperature target - it depends on used voltage controller on Your card, only way to know is simply download and check out GPU Tweak - I recommend using version 2.7.5.0 which can be downloaded from here:
http://dlcdnet.asus.com/pub/ASUS/vga/app/GPUTweak_2_7_5_0.zipIt's more stable than previous and it fixed for me GPU Monitoring app hang and crash.
Here You can learn about other overclocking softwares for GPUs including EVGA PrecisionX and GPU Tweak:
http://www.anandtech.com/show/8589/anandtech-guide-to-video-card-overclocking-softwareAbout overclocking - first start with GPU clock as it gives You more benefit in most cases, benchmarks You can try are: Heaven Benchmark 4.0, Valley Benchmark 1.0, 3DMark Fire Strike and few more, but I find best way to find out stable overclock while playing games - sometime I can pass benchmarks without problems to only get app crash when gaming because of unstable overclock.
I personally use GPU Tweak to overclock my card, reason is that my card is ROG Matrix version and with GPU Tweak I have acces to specific settings which are available for my card like: PEX_VDD, memory voltage, Load Line, VRM clock and 3.3V voltage - these setting can't be set or visible with other overclock software.
However in the past with my previous cards (Asus GTX Titan, Asus GTX 690) I never used GPU Tweak because I somehow liked PrecisionX interface more and there was no difference in setting clock settings in these softwares.
You can try both, I'd try PrecisionX first as it's updated not so long ago with few new features - depends if You like interface look.
MSI Afterburner 4.0 is another great overclock utility worth to try out.
Just remember to use one overclock software at time, as running few in same time can cause several issues. Best to download one You decided to try out, after some tweaking and testing before installing another one use Revo Uninstaller (
http://www.revouninstaller.com/start_freeware_download.html) to uninstall current OC software. Removing software by standard remove in Control Panel may leave services running or other files still on Your system.