but anyways for comparison's sakes mobility radeon 4850 512MB GDDR3
my glxgears FPS stabilize at c. 8200 FPS, and my fgl_glx gears at around 2300 FPS, this is a 500/850 core/mem R770.
I've done ZERO else ATM, and don't really have the heart to test prior bug states ATM to comment on those... no progs run under wine, no games under wine, no video, no sleep, no compiz/beryl, no sleep(power mgmt) testing etc. ad nauseum just plain old 2D unadorned GNOME/Ubuntu variant desktop which still functions OK.
GPU temps: For me they DO run HIGHER than under windows even at the basic windows(vista) performance setting.
e.g. typically unde rlinux even w/ clocks at 250/200 (core/mem) aticonfig reports 56.5C, while under windows it's more like 50C power saving, 52C balanced, 54(ish)C high performance. MSI's turbo battery mode(Vista, I suspect that they underclock but I've not investigated so long as things are working well as it's a pointless triviality) get's me down to 44-46C.
Never really recorded temps under linux while running games or other GPU intensive apps, so I won't bother to mention various peaks here...