Yes, carteron and tonylynch are right. I have Bryce 4 on a an Anthalon 800 with 256Mb RAM and it still chugs for between 16 and 36 hours depending on what it is doing. The last one I did (Women in Lingerie in the Bryce User Gallery) was a 36 hour render due to all the flass used as well as each outfit having 4 or 5 transmaps and then the hair having transmaps. Transparency and volumetric stuff seriously jacks up render time. but, render small as you build and then do a big (I usually do 4000x3000x300 DPI) final render. Good luck!