Thanks Belimawr. Farcry 3 was running ok in the end but every other game I have tried has had issues. Crysis 2 was a bit jumpy, Crysis 3 was dropping as low as 26fps and that wasn't using fraps. Arkham asylum is choppy too. Its defiantly an improvement over my 570 but there are too many issues with this card and dx11.
I am getting ready to send it back tomorrow and have an Asus gtx 780 ti directcu ii oc on order to replace it. Once everything is set up I will start testing again and hopefully this time there shouldn't be any issues. I never had any problems with my 570 so I don't think my computers to blame.
Once again thanks to everyone who chipped in with advice and fingers crossed I don't get any issues with the Asus!