Photoshop performance on new Mac Pro Nehalem

Question

If my current comparison is a dual quad core 2.66GHz "old" Mac Pro, and want new "Nehalem" Mac Pro, where Photoshop performs equally.
Should I get a 2.66 Quad Core Mac Pro (given I accept the 8 GB RAM limit)?
Should I get a 2.26 Dual Quad Core Mac Pro?
Where is Adobe going in the optimizations of Photoshop application and filters?
Will optimizations be done for CS4, CS5, or even later?
Please show me the path.
Søren

Answer 1

Correct
not acceptable.
Phil-
Of course any 4-core Mac Pro with 8 GB RAM and appropriate graphics card will run any version of Photoshop very well, but you miss the point.
"just buy the most machine you can afford" is actually quite complicated.
The point is that we have
multiple Mac Pro computer investment
choices
and prices to choose among:
boxes from 2006, 2007, 2008 and 2009 with various graphics cards and other architectural parameters to consider when choosing the "best" one for any given workflow and financial situation.
With 11 Mac Pros (further complicated by confusing graphics cards combinations) it behooves us to quickly remove what may be
unacceptable investment choices from consideration. The one box of 11 that limits RAM to 8 GB is - IMO - easily identified as "unacceptable" and removed from consideration.
Moving forward :) as app vendors evolve apps to better utilize available cheap RAM, OS 10.6 and boxes with more RAM access (like all the other Mac Pros ever made) ever-larger amounts of
cheap RAM will become more useful. E.g. I paid US$450 to upgrade my 2007 Macbook Pro from 2 GB to 3 GB, and it was worth it. Today that much money will put 24 GB in a MP, and RAM prices continue to fall.
Under OS X Photoshop can already take advantage of at least 32 GB installed RAM. We do not know what 64-bit Mac PS will bring us in a year or so, but odds are pretty high that having lots of RAM available will be very desirable. IMO buying a 4-year-lifecycle pro tower in 2009 that is constrained to 8 GB RAM would be a poor purchase decision.
All the above comments assume heavy graphics app usage like CS3/4/5.
-Allen
P.S.
We agree about the new Mini. Even with its limited RAM (and consequent shortened life cycle) the low price makes it a viable choice for less than the heaviest graphics work.
The new Mini IMO is the sleeper of the new Macs. iMacs are hamstrung by their glossy displays intolerable to many (not all) graphics pros but the Minis are not. Running OS 10.6 with FW 800 connectivity, 9400M graphics, 4 GB DDR3 RAM and third-party displays a Mini can now actually drive a desktop Aperture or Photoshop workflow (although obviously not like a 4x-the-price MP would drive such apps) at a very cheap price.