If a Project uses a lot (and we mean a lot) of digital audio Clips, particularly Groove Clips, the program can bog down when moving/editing Clips. To fix this, increase Sonar's picture buffer cache size.

1. With Sonar closed, use Notepad to open the AUD.INI file (normally in the Program Files > Cakewalk > Sonar [version x] directory, or just use the Windows Search function).
2. Locate the [Aud] section. Underneath it is the PicCacheMB parameter. Set it to a high value, like 500.
3. Save the AUD.INI file.