Work around Photoshop’s 3GB RAM limit

With RAM prices dropping so fast, it seems a shame that I can't really use more than 3GB of memory for Photoshop. As a 32 bit application, Photoshop CS3 can only "use" 4GB of real memory -- a 1GB chunk for the application, leaving a potential 3GB of real RAM available for Photoshop to use for my images. For anyone with 8GB or more of memory, here's an old concept that tricks Photoshop into using as much memory as you want.

Remember RAM disks from OS9? The feature is available in the command line in OS X. By creating a RAM disk, and having Photoshop use that as the first scratch disk, you'll speed up Photoshop as long as you have enough real memory to do it. For my test, I allocated 3GB to Photoshop in its prefernces (real memory usage), and then created a 2GB RAM disk. The Terminal command to create a 2GB drive is: