Went back to the last set of WHQL drivers from nVidia and changed my GPU timings down to 1095/1180Mhz and Ram up to 7666Mhz. Card is air cooled.
Been gaming on these clock settings (Bioshock 1 and infinite and Need for Speed:Rivals) and no issues have arisen. Only in 3DMark11 which hates the Ram clock timings. Firestrike, Valley, Heaven have all been finewith no visible artefacts as far as I could see.
Thats moved you up a bit.
Done.