System Configuration : System Setup : Configuring Pro Tools System Settings

Configuring Pro Tools System Settings
For more information, see the following topics:
Pro Tools lets you adjust the performance of your system by changing system settings that affect its capacity for processing, playback, and recording. These system settings are available in the Playback Engine (Setup > Playback Engine).
In most cases, the default settings for your system provide optimum performance, but you may want to adjust them to accommodate large or processing-intensive Pro Tools sessions.
 
 
Playback Engine for Pro Tools|HD system
 
Playback Engine for Pro Tools with Mbox (3rd generation)