I have 8.4 for Vista 32bit. They seem the same but one problem has arised. I used to get a driver not responding and had to be stopped and restarted error with older 7.X drivers. It went away with 8.1-8.3 but is back. Once the driver kept doing it really fast and caused Vista to BSoD.
my bro uses 8.4 for his 3850 512...he says it works fine for eq2...quite an improvement over the x3100 in his dell!!! he crapped his pants when he got it all together and working!!
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msi k9a platinum
x2 4000+ brisbane
patriot extreme ddr2800 cl4
stock air until i get new pump