7950 problem

Hi there I brought a sapphire 7950 vapour x which I seem to be having strange problems with
When I first installed it I formatted HDD and reinstalled everything ,and since then my startup has been going very slow ,PC generally going slow and problems with games the main game I have been playing is xcom in which I have had problems with the multi layered ships (which was the only actual graphic issue) crashes/very long load times or pauses in game and also things dissapering/not displaying correctly like my chance to hit the alien displaying 1% and no health/damage counter above my soldiers when shot ,I changed back to my 5830 and most of the issues there went away but the game still crashed ,also in the switcher 2 I couldn't talk to anyone in a village and minimap vanished
Unfortunately I can't RMA this card so I have tested it with
Atitool for over 1.5 h and had no issues with exelent temps only 53c with fan at only 43%
I also tested it on 3d mark11 twice once right after the 1.5h of anti tool and yet again no issues and scored about 7800 GPU score which is average for 7950
So I was wondering if it could be something else or I am doing something wrong here
I am running the latest drivers
And have a 650w xfx XXX PSU
Win 64bit