Ok, i just got my spanking new rMBP as a portable gaming machine after hearing all the raves about its insane gaming hardware and in particular the highly clocked 650M. Thus it came as a surprise that games, however smoothly and impressively they run initially, start to jerk and transition between different 'frame rate classes' after a while. For instance in GTA4, i could be cruising on the highway at 40fps and then have frames drop to 20fps for a few seconds before it coming back to a smooth 40fps again(a few secs later this will repeat). Once this 'mode' has been entered(which could be after anything from 10mins to hours of hard gaming), it'll annoyingly stick till the next reboot. Thoroughly annoyed, I assembled all e gpu diagnostic tools i knew about and did some testing. As in e ss below, i believe i've pinpointed the problem down to GPU throttling even as i'm still unsure what's causing it. As can be seen, clocks struggled to maintain at the 'advertised' 900mhz speed even for a while after the gpu intensive unigine bench was started. After a while we could see it starting to throttle between 900 and a couple of clock states below it(this could be the state where I witness 'jerking' in games), and finally stabilizing at a not-so-impressive 725mhz clock state. All the while I've monitored cpu/gpu temps and they are all pretty much 'safe'(both don't go below 80deg). In fact, looking at the log, it seems throttling occured when temps were at their lows, thereby ruling out any temperature related cause. All in all, I'm amazed that there are others on this forums and the internet who've managed to massively overclock(one even reach an insane 1200/17xx) and reach bench-stable states on this card even as mine is struggling at stock clocks. Perhaps this could be a unique defect with my set or a personal setting/config gone wrong somewhere. Would be great if the macrumors community could assist in helping me nail down the root cause of this crippling defect, and avoid me having to lug the set down to the store and argue my case.