hi I have gigabyte hd7870 windforce 3 edition. I am having no success with oc at all and considering the supposedly great oc ability im disappointed. don't get me wrong, the gpu is not a disapoinment, its great but it will not oc. using after burner I can get the oc stable at 1170 core and 1450 vram with 1250 volts but find after burner gives me lots of annoying black screens. I uninstalled it and used overdrive, seemed stable all day at 1150 and 1450 with 20%+power, not one black screen gaming all day @99% use in crysis 2then its just froze in I player oddly. Any suggestions? with the price drop I intend to xfire this week sometime. should I just leave them stock? is it worth the hassle for such small oc`s? or do I just have a poor oc card above the factory oc. thanks in advance