well my video card is a little older than 2 weeks its about a 3 weeks old, but anyways i drilled some holes in a giant socket a cpu heat sink that was just laying around, and mounted it to my x850xt along with some artic silver thermal compound and my video card doesnt break 50c underload and this is 540mhz on 16 pipe lines, i hit 6520 in 3dmark05, this thing is killing my old 6600gt. i mean what an upgrade. oh and the cooler costed me nothing lol. so it all wroked out great, and i mounted a red ultra 80mm fan with a chrome grill on the heat sink so it looks pretty sweet lol. oh and just becasue he got higher clocks than you with a 6800gt also doesnt always mean your core is running hotter. some cores just wont push but so much. my core is done with at 540mhz! i mean it wants no more lol. but my brother with the same video card as me runs his core hotter than mine and hes pushing 590mhz but cannot go anyhigher because lack of voltage, and his system will lock up. so he could possibly get it even to 600mhz, becasue the video card will not artifact just system lock. hopefully the new ocz 520 watt mod stream hes waiting will take care of that lol.