Jerky unresponsive display FirePro V4800

Hi Everyone.

I am experiencing some delay on my display from input on the keyboard / mouse.

It affects everything, from the viewport in my 3D application (3ds Max) to playing videos, even using my email program!

Yesterday, I also had a bluescreen error. :-0

don't think it's anything to do with the mobo / OC. Temps never get over 70 C

My specs are as follows:

Cryo PC Tetrad -

Gigabyte GAX79-UD3
Intel i7 3930k 4.5Ghz
16Gb Ram
Firepro V4800

Many thanks in advance for any help