670 power edition overclocking/volting

My gtx 670 power edition doesnt seem to be able to overclock well, the most I can push it to is about 1188mhz (+20) and 3649mhz memory clock (+500) I can increase my memory clock to about +640, but im worried about it reducing the life due to the excess heat. The main thing is my core frequency, 1188Mhz seems to be pretty much as high as it will go, Ive raised my voltage to max (1.175v) and my power limit to max (114%) and still It wnt push higher, my games just blackscreen, then come back 2 seconds later all laggy, and msi kombustor burn in just crashes and a windows error comes up if I go to say +40mhz any idea's why? I have the latest drivers, and my card isnt throttling, its stable at 60 degrees centigrade.


First off turn down the memory clock, it seems ridiculously high. Also set everything to default and increase the gpu clock a bit at a time, once you find something stable make the memory clock go up around 400, you won't notice any big differences if you go any higher. I got my galaxy gtx 670 Gc to 1250 mhz, and everything is stable. Lastly make sure you  are useing evga precision X and that nothing is overheating (set your fan curve in there as well).