GTX 670 Reboots PC When Gaming

[jauer]

I recently got an Nvidia GTX 670 (Gigabyte Windforce X3 OC) although it does not seem to like gaming... display works fine from it, although whenever I open a game or benchmarking software (anything GPU intensive) the PC simply reboots. This could be after I leave the menu for gameplay/benchmarking, or as soon as the program starts up. I'm fairly sure it isn't to do with my PSU (which other similar questions seem to be answered with) as all calculators say that I have around 50W leeway still. These are my PC specs:
MB: Dell Optiplex 790
CPU: Pentium G630
DDR3 RAM: 3x 4gb 1x 2gb (14gb)
PSU: Corsair VS 450
GPU: Nvidia GTX 670
I'm running Windows 10, and the 384.76 driver recommended by the Gigabyte website. Any ideas? Any help would be much appreciated!

 

[sadams04]

You might be tired of hearing this, but..... The GTX 670 was a bit power hungry and is recommended to be paired with a 550w PSU or higher. Your Corsair VS is an OK unit (not the greatest), but it may not be able to keep up in high demand situations. That 50w of headroom will quickly disappear when temps start to rise in the case (the 450w rating comes at a lower ambient testing temperature). It is also possible you have a bad GPU that is causing a fault (and rebooting).

Regarding your memory... you are running in single channel mode (reduced performance) with your mismatched modules. It would be best to find a matching 4GB module to have 4x4GB to take advantage of the dual memory controllers and run in dual channel mode.

And... your G630 is really holding you back. The OptiPlex 790 isn't a bad platform being a bit older now, but maybe check the used market for an i5-2400, i5-2500 or i7-2600 for a good bump in performance at a (hopefully) low cost.

 

[jauer]

Thanks for the response - I've ordered another GPU in the the hope that that will sort it out. After that if the problem continues, I might get a new MB (as this one has been giving me trouble anyway) and look into a better CPU. Thanks again!

 

[jauer]

Sorry for being so sceptical before about the PSU... I've just got a 650W EVGA and it all works fine.