Stuttering and low fps in games

[Tophat]

Hi, my pc is as follows:
i7 4770k
8Gb ddr3 kingston hyper x genesis
GTX 970
Corsair 1200i

For some reason I have been getting major lag in games since installing the 970 followed by some strange white patches that randomly appear in games. They look like missingno around the screen if that makes sense. The desktop is fine though.
My previous card was the 770 and I was under the impression that the 970 would outperform it but so far it has been about 12 fps lower.
Any ideas? Thanks.

 

[TheGeeza]

Try a clean install of the drivers. What are the temperatures like in game?

 

[Spuff]

It's definitely not normal, my 970 easily beats my previous 780 OC and has achieved rock solid 60fps on both games I've played with it so far.

 

[Tophat]

@TheGeeza
Thanks. Drivers were the problem.