first off, afaik, bryce's own render calculations are accurate only for short renders. know you're gonna deathkneel it with some 18 hour render and it's gonna be way off. that said, i have absolutely no idea what those numbers mean, in 5 years of brycing i have never bothered to check them. i just figure out how long the nano-preview takes to render and how long the first rendering step takes. based on the latter, theoretically each sub-pass will be at least twice as long. which gives me a pretty good idea. drac (doesn't really help)