Graphics freeze momentarily every second

[Cantoris]

I was using Nvidia's own v275.33 driver.
I've now just gone to the Asus site and downloaded their v259.44 version which is the newest one listed for this card. It dates from March this year.

The problem is now fixed!
Interestingly, my graphics scores in the Windows Experience Index have gone from 5.7 and 4.3 to 5.9 and 5.3!!

Thanks for your help.