I have a color correction layers with a mask, when I try to run levels or curves Photoshop gets real slow. This happens on most any file and sometimes it works fat and then gets in a rut and slows down to to taking 5 minutes after pulling a slider.
I have tried:
setting my histogram and cache levels to max performance
disconnecting from network
I am on a G5 2Ghx 3GB Mac OS 10.4.8
PSD version 10.0.1
The current image is only 240 Mb