Originally Posted by jpterj
I am not asolutely sure about this but I suspect that this might be a memory bandwith issue.
That might be the problem. I'm not sure tough.
I'm using an AMD cpu (one of those energy efficient ones; forgot the exact model) which I keep at its minimum frequency with powernowd. A user in another forum suggested throttling the cpu to its maximum when playing 1080p stuff to increase performance. I've just tried it an it certainly helps; I mean, the video still has some hiccups here and there but audio and video keep in sync, contrary to what happened before.
I guess I'll keep waiting for nvidia engineers to improve linux drivers for some time and, if the situation doesn't get any better, I'll buy more capable hardware.