I think it is strange that a dream with a size of 4 mb needs 15-25% cpu (l8raysdark) while another one at 140 mb only uses 4-8% cpu (FractalFountain) 

Maybe the codecs i have installed are slower than what other use or the codecs that are used for the dreams are not the best to use for dreams. I use K Lite Codec Pack.

Lets say that wmv uses 25% and mpg 15%, maybe it has nothing to do with it but if then i think it would be best that all dreams used mpg instead of wmv. 

Vista Home Premium x64, Core 2 Duo 2.66 @ 3.6 GHz, P35 EP35DS4, 4GB DDR800 @ 900Mhz, GF 8800GTS 512 750/2100/1800.