I did it! The CPU saturation challenge is complete. Those blue graphs at the top represent the CPU cores’ usage, as displayed by MenuMeters.
It’s not 100% of all cores, but it’s close enough.
This is ripping a DVD with the new version of HandBrake to the AppleTV H.264 preset.
It’s worth noting that even with the CPUs at full usage for sustained periods like this, the fans aren’t spinning up to full speed. I don’t detect any difference at all. A real test didn’t, either. The Mac Pro is encoding video about many times faster than my 2 GHz Core 2 Duo MacBook in almost complete silence (certainly not noticeable above ambient room noise).