Logic: Save CPU when muting channels

Logic 9
Go to Preferences / Audio / General / then  Track Mute / Solo

Set it to CPU Saving to free up resources when you mute or solo a channel.

Logic 8: disable track when muting (to save CPU)
In Logic 8 when a channel with plug-ins is muted it still uses CPU resources. You can change this so that when a channel is muted Logic "disables" the track hence freeing up the CPU.

Go to:

Preferences / Audio / Mute Solo / Slow CPU saving