I have an old Athlon 800Mhz PC with a Matrox G450 video card here that is used for watching DVD and video, for most part it works quite fine, but every two seconds the video playback stops for a fraction of a second. It's a tiny but noticeable and annoying glitch.
CPU usage doesn't seem to be the problem, there isn't any major IO going on in the background and no obvious background process that could be causing this. Starting the playback with 'nice' or a larger cache (
mplayer -cache ...) didn't bring any improvements.
The machine is running Ubuntu 9.04, under Windows98 the problem does not appear and video is fluent.
What could be the cause of this problem and how could I try to debug this further? My current guess would be that its hardware/irq related issue, but thats pretty much just a blind guess.
Edit: The problem seems to have disappeared, sadly I have still no idea what solved it or what caused it in the first place.