On 8/16/05, Michal Hajek <[EMAIL PROTECTED]> wrote: > If I run setiathome and glxgears at the same time, I get 10 fps. But if > I kill setiathome and run only glxgears, fps immediately jums on > 2500 or even 4000 at times.
It could be a scheduling issue. I assume that every frame needs a context switch between your application and the X server. This is very likely caused by a command sent to the X11 server, and the application waits for the result before the next frame is painted. Of course the X server cannot service this command unless it is running, which requires the application to be put on hold. But since setiathome is also running, it might get a slice of CPU time in between, which is usually around 20ms, but could be longer. This is a known problem of the UNIX scheduler, and the best solution so far seems to adjust the priorities or to go multi processor. I would try to renice setiathome to a lower priority, and see whether it makes a difference. Some distributions also run the X server with a higher priority (-5) to help a bit. Thomas
