Good ole' Bare Feats has just published a set of benchmarks
comparing the performance of a 2.66GHz Mac Pro, a 3GHz Mac Pro, and a 2.5GHz quad-core Power Mac G5 at running both Universal
OS X applications. While it was no surprise that the Mac Pro notably surpassed the Power Mac in Universal application performance, the former's ability to run Photoshop CS2 under Rosetta
was surprisingly impressive.
We don't want to spoil it for everyone, but some concluding remarks from the article are indeed rather telling:
There's no doubt that both versions of the Mac Pro are faster than the G5 Quad-Core running Universal Binary apps like iMovie, Final Cut Pro, etc. As you can see from the four UB tests we ran in this session, the Mac Pro 2.66GHz was as much as 62% faster than the Quad-Core G5/2.5GHz. The Mac Pro 3.0GHz was as much as 85% faster.
AnandTech has also posted a review with benchmarks
of Apple's latest pro tower.