Improve Performance

Make the iMovie window smaller. Drag the resize handle in the lower-right corner of the screen to make the window smaller.

Quit other running applications. iMovie and iDVD will gladly use as much memory and processor power as you can throw at them. If playback is sluggish, try running only iMovie or iDVD.

Delete the program's preferences. If iMovie or iDVD crashes, its preferences can become corrupted, causing more problems later. Here's how to delete preferences:

1.	Quit the application.
2.	In the Finder, choose Home from the Go menu.
3.	Open the Library folder.
4.	Open the Preferences folder.
5.	Delete the following files (you may not have them all):

iMovie Preferences

com.apple.imovie.plist

com.apple.iMovie3.plist

com.apple.iDVD.plist

Turn off FileVault (Mac OS X 10.3 and later). FileVault is a technology introduced in Mac OS X 10.3 Panther that creates an encrypted version of your Home directory to secure its contents from snooping eyes. The problem is that iMovie and iDVD store their project files in the Home directory by default. So, when FileVault is active, the computer is constantly encrypting and decrypting massive quantities of data on the fly. Turn FileVault off in Mac OS X's Security preference pane.

Make sure you have plenty of available hard disk space. I can't say it enough. Digital video requires huge amounts of disk space. Consider buying an external hard drive and storing your projects there; if your Mac includes a FireWire 800 port (a faster version of FireWire), get a drive with FireWire 800 support.