I know Posers 4's rendering engine is not Multi-threaded, and my suspisions are that neither is Bryce 4's. However, a multi-proc system should help you some. Win2K and NT 4.0 should load balance the rendering thread onto one proc, and operating system threads (or other program threads) onto another. A Windows application can only take advantage of multiple processors if the app is written multi-threaded. Metacreations is great, but not multi-threading the rendering engine is a crime. And I don't think the implimentation would be that difficult. (Not near as difficult as writting the ray tracing engine, anyways). My guess it that they try to share as much code as possible between the Mac version and the Windows version. And multi-tasking on the Mac operating systems works quite differently from the way Windows does it. It's a damn shame. -Nik