On Tuesday 21 November 2006 18:50, Fons Adriaensen wrote: > It comsumes a lot of CPU if you use many channels. > On my 2 Ghz P4, 16 channels take 94%. Almost all of this > is taken by X11, which indicates that there's something > strange. I assume you're using SDL. If you can, try OpenGL, that should take most of the work off the CPU. Apart from that... well, redrawing the entire window, 50 times a second by default, is expensive (although I'm sure there's a lot of room for optimization). Depending on what you're trying to do, a lower frame rate might suffice, and reduce the CPU load significantly. Another thing you could try is to change both occurences of SDL_HWSURFACE in video.h to SDL_SWSURFACE. Does it make any difference? On my machine it doesn't, so I wasn't sure what to use. Also note that currently, even in non-scrolling mode, jack_oscrolloscope redraws the whole window on every frame, because was easier to implement. Changing that is somewhere on my todo list :) Dominic