Thanx for that link Xie67 it is very helpful! I have got a new gfx cooler, the Zalman VF700-AlCu and it works a treat
Pretty easy to install and very effective at what it does! I think coolers definitly make a difference to overclockability. Before getting the zalman i could only clock to about 515/540 before i would get artifacts, but now i have been able to get XT PE setting and then some!! I'm keeping it at 520/560 for the moment, but next week i will try this voltage mod. I've seen some out standing 3DMark05 benchmarks scores in the 7000's with core speeds of 600+ so remain optimistic as to what I can get
at the moment when i try to OC to 535 the card locks up and i have to restart, hopefully the voltmod will improve that.
Have you tried voltmodding?