Load temps very high (90c) HD 7770

Hey guys, until recently my GPU has been fine under load (~60-70c) but now it's peaking up to 96c when under heavy load. I haven't done anything I can think of to cause this issue, but I remember updating my drivers and it started to happen. This may have been a coincidence since I rolled back the drivers through windows (is this the wrong thing to do?) and it's still happening. Today I'm going to buy a CoolerMaster SickleFlow fan, I have a Fractal Design Core 1000 and there's a fan mount on the side panel, directly above where my GPU is (ASUS Radeon HD 7770) so i'll see if that helps. Anyone know any reason it could be happening? The GPU fan speeds up a hell load when it's at 90c, and it sounds like a bootup fan rpm, then the temps drop by like 10c. 

Please can somebody help me out here? 

Cheers,

Elliott

have you tried cleaning out the fins or re-applying the thermal paste? that might be some of the issue, if that is not the case since it is a fairly new GPU then i suggest looking at the fan and checking the speeds.