Very good idea to let 64 machine do the job together. BTW. check out TeraBits mods to the ICU algo, if I remember right he used to make it run 20 times faster or so. It was in some thread about VIS occlusion where he told me how to make it real fast. I guess it had something to do with the fact that access to the backbuffer is much slower than - some other buffer :) which I don't recall atm. Probably an imagebuffer, or a vram-persistant texturebuffer?