I've tried using both RecordMyDesktop and Istanbul to do some video capture of applications. On my home PC (openSUSE 11.3) then RecordMyDesktop has terrible performance and doesn't capture most of what happens (close a window and re-open it and if you took long enough then it might disappear briefly in the video) but Istanbul does okay, even with capturing Compiz effects. On my work PC (Fedora 13) then Istanbul is passable, but the mouse movements are jerky even under Metacity, where as RecordMyDesktop does clean and smooth captures, even with Compiz effects.

Does anyone know why different apps would perform so differently on the two machines? They're both quad-core Intels with 4GB RAM and nVidia graphics cards with recent versions of the proprietary drivers.