Xbian still my favourite RPi OS

[mk01]

if you guys are running such intensive concurrent apps, you can play with niceness.

renice -15 -p $(pgrep xbmc.bin)

will set the niceness for xbmc.bin processes. default niceness for processes is 0. you can change from -20 to 20.

THE LESS NUMBER THE HIGHER prio.

system processes and threads use to have -20, so don't go there, but feel free to use -15 to 20.

I would put transmission definitely above 10 and xbmc around -15 to -7 (at minimum).
this is to experiment for everybody, everyone is running different processes, or clocking.