I doubt it's the cpu, 1.26v is a relatively low voltage even for 24h usage. I would check nvidia drivers (roll back to 314), psu, mobo in that order. Bad memory is also a possibility but it usually comes with blue screens. The latest nvidia drivers have been a nightmare for me making one card overheat and constantly crashing another pc. Read this :
The psu is another strong possibility, especially since both your gfx and your mobo are acting up. I've had a TX650 seasonic model cause freezes when idle after only 3 years of usage, unfortunately **** happens as they say
Now, your mobo has excellent vrms so it's less of a likely suspect but your bios might be corrupted. Switch to the backup bios chip, turn of your psu, unplug it, hit the power button, remove your battery, reset cmos, wait 5 minutes and replace the battery. Load optimized defaults and check stability. Run a few hours of memtest to get this possibility out of the way. If all goes well, reapply your settings manually (make sure you don't load them from a saved profile) just to make sure.
I'd also suggest overclocking your cpu via offset and turbo, it will greatly extend the life of your 3770k.Edited by SkiesOfAzel - 11/16/13 at 3:12pm