I order two of these card to run in SLI . first issue I be not aware of be that Intel X79 chipset be not currently support by Nvidia to run at pcie gen3 speed . OEM distribute driver allegedly allow pcie gen3 speed but official Nvidia driver do not . I believe this will be fix rather soon and be a mute point for the most part . next , the current Asus GPU tweak software -lrb- as of 3june -rrb- appear to be cause many user issue to include a red screen of death -lrb- rsod -rrb- . I experience these issue and they be resolve immediately by uninstall the Asus software . the bigger issue be that overclocked 670 's in general at this point be like play the lotto . I order two and one run great while the other could not complete any benchmark at factory speed without crash and will be return . before figure this out , I read many forum with user report the same situation . underclock the card will make it stable , but I pay for a card that be guarantee to work at a certain overclock . the good stuff ; the card that run , run great ! at factory fan speed and under full load for half a hour -lrb- prime95 & furmark -rrb- I see temperature around 66c . with a 4.7 ghz Intel i7 , I get 9500 mark in 3dmark11 . I have many newer game if anyone want specific bench for certain game . I have not experiment with overclock with either card as most review indicate the card be pretty much max out as be . I be switch from a ATI 7950 -lrb- Gigabyte Windforce -rrb- . the 7950 at a max overclock be slightly faster than the 670 gtx in my experience . however , amd\/ati suffer from many driver issue and game do not typically scale as well in Crossfire as they do in SLI . of note though , the AMD card do appear to render higher quality graphic at default setting . I would not recommend switching from a AMD 7000 series card to a Nvidia 600 series card but anything else will certainly be a huge step up . one star deduct as the qa of the card be not great at this point .