MacPro slowdown - request additional diagnostication suggestions

Question

Friends:
I'm diagnosing the extreme sluggishness a MacPro running 10.5.8 (2x2.26 GHz Quad Core Intel Xeon with 6Gb Ram and 1066 MHz DDR3)
I ran Drive Genius 3 and Verified, Repaired, Rebuilt and Defragmented all internal drives. All reports from the application were that all is OK.
The computer runs well during the first half hour, but later it beguns to slow down. Beach Ball on almost all selections, and when you insert a flash drive it takes at least 5 minutes to show up on the desktop. When the machine is restarted all things including flash drive mount are fast as expected.
The main applications used on the Mac are Adobe Creative Suite CS5, MS Office 2008 (fully updated).
Software Update is all up to date as well.
I have even tried formatting the boot disk and reinstalling the OS and applications, but the results are the same.
Right now the only option is to restart the machine every half hour to keep working.
What would you all suggest as a next step in identifying the problem?
Thanks for all your suggestions,
Migs
Message was edited by: Miguel Reznicek

Answer 1

Perhaps the mac has too many files on the desktop? (500Gb of images or so)
Almost certainly.
Performance tip: Keep the Desktop clutter-free (empty, if possible)
Mac OS X's Desktop is the de facto location for downloaded files, and for many users, in-progress works that will either be organized later or deleted altogether. The desktop can also be gluttonous, however, becoming a catch-all for files that linger indefinitely.
Unfortunately - aside from the effect of disarray it creates - keeping dozens or hundreds of files on the Desktop can significantly degrade performance. Not necessarily because the system is sluggish with regard to rendering the icons on the desktop and storing them in memory persistently (which may be true in some cases), but more likely because keeping an excessive number of items on the Desktop can cause the windowserver process to generate reams of logfiles, which obviously draws resources away from other system tasks. Each of your icons on your desktop is stored as a window in the window server, not as an alias. The more you have stored, the more strain it puts on the window server. Check your desktop for unnecessary icons and clear them out.
Keeping as few items as possible on the Desktop can prove a surprisingly effective performance boon. Even creating a single folder on your Desktop and placing all current and future clutter inside, then logging out and back in can provide an immediately noticeable speed boost, particularly for the Finder.
And it is why Apple invented 'Stacks' for Leopard.
Here is Apple's take on the subject:
http://www.apple.com/pro/tips/immaculate_desktop.html