My pc started shutting off the graphics card after about 1 month of use with a black screen, I had to turn off the power switch to reboot my still running computer. It seemed random at first while running the DX-11 game, WoW. After setting the nvidia graphics to high performance it would still happen, and again after changing a few driver sets using 3dguru's driver cleaner. Reading a few posts about using afterburners fan controller i experimented with precision x16's manual settings which helped a little, then i tried setting the fan minimum speed up a little in auto and it helped some but still shut down. What seems to have helped the issue for me was setting the Auto speed control's minimum speed to 63% and changing the fans  curve editor to a straight diagonal line(no curves or dips)from 63% to 99%. Watching precision x16's fan speed indicator showed that the fan was ramping up way to slowly from 43% before, if at all. Changing the fan low speed setting and ramp up curve seems to have re-enabled the automatic fan control with precision x16 running.  For some reason the card was stuck at about 43% fan speed most if not all of the time. It now idles at about 35C at desktop , playing WoW WoD beta on Max settings at 1080p its staying in the low 50c range with fans running in low 80% range. It started the crashing with black screen lock ups again after about a week of stability, was running the 344.48 WHQL drivers rolled back to 337.88 WHQL running stable for the moment.
 
System is a amd phenom ii x4 955 95 watt cpu, a gateway RS780 motherboard with latest bios , EVGA GeForce GTX 750 Ti 2GB w/ EVGA ACX Cooler superclocked, 8 gb ram ,corsair tx650w power supply, windows 7 home premium service pack 1