Hoping you may be able to give me some advise. I purchased a Sapphire 7970 pretty much when they came out, waited a week for the EK waterblock and fitted it. I was lucky, using trixx i could overclock to 1335/1625 1.25v with no problems. It has run happily ever since, although i use 1225/1525 for everyday gaming. I updated to the 12.11 beta driver when it came out and got some great improvements. I noticed a few weeks ago a buzzing from the card when under load. I googled the problem and found loads of people reporting similar problems with their 7970's. I did a couple of 3d mark11 runs and started to notice a few problems i.e slight artifacting and random crashing to desktop with 'display driver recovered' messages. I had ordered a new ssd which arrived on friday, so i did a fresh install of windows 7, loaded drivers and trixx and reset the clocks to 1225/1525. Running 3d mark11 now gives massive artefacting as does Heaven. I then reset clocks and voltage back to stock in trixx and ccc and the artefacting is just as bad. I hav'nt tried a game yet but fear the worst. Has anyone experienced anything similar? Also i'm guessing that by fitting a waterblock, i've voided my warranty? I purchased the card from ocuk .