well, the current version of Bryce works fine on a multiprocessor, it just doesn't take advantage of it. And unless they completely re-wrote bryce 4.1 to be fully multithreaded (which I'm highly doubting), then the performance improvement should only be marginal. The big gain you'll see is using Bryce and some other program at the same time. Hopefully, the next version of Bryce will be niftier and will try to render multiple passes all-at-once with the multiple processors. I don't think that capability is in the 4.1.1 release, because that would be a major re-write.