Mac Pro results: Boot Camp XP versus Rosetta
Okay, I finally got around to running this on my Mac Pro, which is the 2.66GHz model with 2GB Apple RAM (4 x 512MB), 7300 GT model. The OS X/Rosetta test and XP/Boot Camp tests were both done with history states set to 1 and 70% of the RAM allocated to Photoshop. Windows was installed using the method posted in the forums (using nLite to embed the SATA drivers into the XP installation).
And the winner is... XP/Boot Camp! This was a bit of a surprise to me since the HD access times in Boot Camp still aren't quite up to what they should be. I guess it shouldn't have been since the OS X version was running in emulation. Photoshop took 1:24 in Rosetta and 1:00 in XP (29% faster).
Additional details of testing: Both tests were done immediately after a restart. The Windows installation is on the 250GB WD drive that came with the Mac Pro (8MB cache, 7,200 rpm). That drive is partitioned so that the OS resides on a 30GB FAT32 partition and the remainder is NTFS. Photoshop was set to use the NTFS partition as scratch disk. I'm not sure if that matters. OS X is on a separate 320GB WD drive (16MB cache, 7,200 rpm) which is unpartitioned.
I found the results quite interesting and was pleased with both Rosetta and XP performances. I continue to be pleased with the performance of my "old" G4 Powerbook, which as I mentioned above got 3:03 on this test.
Addendum: One more observation - Based on Activity Monitor, PS under Rosetta is not only taking advantage of all four cores during this test, it is using them all just about equally and at times near maximally.