Comiz and Kwin effects offload to GPU

Ok guys,

I pose this question: Does KWIN or Compiz fusion actually offload the graphic work to the GPU or the CPU?

I have my doubts. Example. When i check xorg, everytime i move a window with wobbly effects or move desktop (this is KWIN) the XORG CPU jumps. When i have multiple monitors, xorg uses 500MB of memory!!! I wonder if these will ever USE the GPU like its suppose to!!