While it’s not an every time thing, we run out of RAM when designing complex graphics. When this happens, Photoshop and After Effects turn to your scratch disk for virtual memory. Don’t overlook this important setting, or your design session can come to a screeching halt. In fact, it’s worth adding an extra internal drive if you’ve got an open slot.
In Photoshop:
1. Press Cmd+K (Ctrl+K) to call up the Preferences window.
2. Switch to the Plug-Ins and Scratch Disks tab or press Cmd+7 (Ctrl+7).
3. Choose up to four Scratch Disks. Avoid using your startup volume if possible.
In After Effects: (6.5 and later)
1. Press Cmd+Opt+; (Ctrl+Alt+;) to call up the Preferences window.
2. Switch to the Memory & Cache tab .
3. Check the Enable Disk Cache box.
4. Set a Cache size in MB.
5. Choose a folder on a hard disk (not a drive itself). Avoid using your startup volume if possible.