With my 700 I hit 1G, I had to run it at 1.85v. I didn't test it a whole lot. Ran 3DMarks, Quake3, it ran those without crashing. I spent a night playing with all different combos, benchmarking and what not. But after I benchmarked about every speed known to man, to difference speed wise between 850 and 1000 was not worth how much hotter it ran. About 31C@850 and 39-40@1000.