SOLVED: iMac 27'' (Late 2009) Poor Performance and Flash Issues w/ SOLUTION

I was able to cure all my performance issues by doing a low-level power/video/parameter reset (NVRAM/PRAM) to my iMac 27'' / 3.0Ghz / 4GB / ATi Radeon HD 4670 256MB

I had the following symptoms:

 Ridiculous boot time (5-6 minutes)
 Sluggish behavior in all window-based operations (hide/show/open apps; switch apps; open new windows, docs, etc.)
 Abhorrent Flash performance (even worse than usual for Flash)
 Xbench score = 124.22 (pathetic)

Steps to cure:

1) Shutdown iMac
2) Unplug power cord from back of iMac
3) Press and hold power button for 20 seconds
4) Restore power cord; power on iMac
5) Immediately on hearing Startup Chime, press and hold Command-Option-P-R keys (⌘⌥ P R)
6) Wait until you hear an additional four (4) chimes; the fourth (fifth) chime will (should) be louder and clearer
7) Release the keys and allow iMac to boot normally.
Note: This reboot may take up to two minutes, but subsequent reboots should be less than 30-45 seconds.

Results:
 Boot time 35 seconds
 super snappy app/window behavior (especially Parallels/Windows and Safari/Flash
 New Xbench Score = 286.24 (must admit I thought this would be higher)
 Super Happy owner of the hands-down, most kickass screen on the planet
HTH

Frederico

Message was edited by: Frederico