The Online Photographer put together a great piece on using an external hard drive to speed up Photoshop performance.. basically utilizing it the external as your scratch disk. I’ll definitely be trying this. To see how you can turbocharge your Photoshop, click here.
I have a few external drives but they’re all USB2 unfortunately. There’s no way I could consider using them as a scratch disk, but using a second disk where your OS isn’t installed is always a good idea.
I use a laptop so I’m stuck with one internal drive. Does the job well enough especially as USB2 external drives are cheaper here.