now the main problem with that is, i'm guessing you're using maybe atitool or amd gpu tool, and you're changing 2d clocks, because stock 3d clocks are 743/825 for all 512mb versions, and higher for the 1gig versions.
anyway, most people find on air the core will do 800 and mem does in general 900 at least. a lot of people have around 800-850 on core and 950-1000 on the core.
i've still not got around to playing with voltages on atitool, not even sure they work. not really seen much talk of safe voltages anywhere so been putting it off.
anyway, on stock cooling a decent overclock seems pretty damn easy. at some point better cooling will be needed. i've got mine on watercooling and get very very similar clocks to without watercooling despit earound 25c lower load temps. so fairly sure i'm voltage limited for a larger clock.
