12 hyperthreaded cores!
My new 12-core Mac Pro is almost ready (it's been copying files from my other machine for nearly 24 hours now). I re-ran a [MPEG Streamclip vs. Compressor](h/journal/2010/08/14/transcode-war-mpeg-streamclip-vs-compressor/) test and was pleased to discover Compressor is now insanely fast because it can be configured to use all of the cores. MPEG Streamclip doesn't seem to multithread properly to use all 24 virtual cores when only batching up a few clips. I set it to 4 instances, and combined processor usage was around 270% (out of 2400%). Running the Compressor job against a local QuickCluster resulted in CPU usage illustrated in the screenshot above.