Does anyone know if CS6 does actually properly support multi-core processors?
I've got a MacPro with dual 6-core processors and it does seem much faster than CS5, but people are saying that's due to the new graphics engine.
Are you sure it's just that because it really is much faster?
There seems to be no mention of multi-core anywhere which is a bit suspicious.
I recently upgraded from a dual 3Ghz quad core MacPro with which was about 5 years old and my new machine which is the top pf the current MacPros with the full 64 gig of ram and SSDs, did not seem that much faster - Until I started using the CS6 beta.
I checked on a PC with i7 3930K a few days ago, and Photoshop was using six cores, but only six threads out of twelve showed any high usage. I did wonder if it was other apps or the OS causing the little bit of activity in about two to three of the remaining six threads. As for dual processor systems, ISTR Chris Cox saying something about them in the Photoshop General forum a while back, along the lines of you would not expext full usage of both CPUs and all available threads. Incidentally, CS5 shows the same CPU usage as CS6 on my system. Perhaps Chris will be along to give you a heads up on that score.
Photoshop has properly supported multicore systems since Photoshop 3.0.
So, no, there wouldn't be any mention because it's hardly something new.
And on a hyperthreaded system, some operations can make good use of the hyperthreads and many can't.
Also, bugs in the MacOS kernel prevent MacOS from making great use of hyperthreads (things that run faster on windows run slower on MacOS if you try to use all the virtual cores).
I guess, there is some change. Take a look at the lens blur filter. Either it didn`t use more than one core in CS5 or it did not use many cores very well. In CS6 all cores nearly max out and it`s so much faster. I`ve also seen optimitations in other commands. As far as I remember, one of them was merge to HDR. But Chris knows better.