Quote - In October 2006, DAZ released Bryce 6.0 and has released an update (6.1), this includes a Mac Intel compatible update. New features include animation import, support for dual-processor systems as well as hyper-threading, random replicate tool, advanced terrain editing, HDRI support and other tweaks. The interface remained largely the same, but with a green tint to it, and different buttons in the create palette.

Ok so I've been looking at what else I can do to increase performance and noticed this blurb on Wiki and what stood out for me is that Bryce now supports Hyper-Threading.

The PC's that I have are Pentium 4 HT's, I wonder if Bryce Lightning does indeed support Hyper Threading.  If it does I can enable and hopefully get more performance per PC.