Pro Tools is a software version of a digital audio workstation from Avid Technology that runs on both Macintosh and Microsoft Windows operating systems. Recording industry professionals use Pro Tools to edit and record sound for movies, TV shows, and concert halls. Depending on the features of Pro Tools used, the number of plug-ins available, and the number of cores in your computer's processor, you may experience delays or out of memory. Here are some steps you can take to allocate more memory for Pro Tools tasks.
Steps

Step 1. Close all applications
To get the best performance from Pro Tools, close all open applications on your computer. This frees up RAM and other available resources for Pro Tools to run.

Step 2. Configure the parameters in the Playback Engine window
To free up memory, you can change parameters such as CPU usage limit, RTAS (Real Time AudioSuite) processors, hardware buffer size and DAE (Digidesign audio engine) buffer size.

Step 3. Open the Playback Engine window
Launch Pro Tools, click on "Setup" and select Playback Engine.
- Change the CPU usage limit. In the Playback Engine window, click on the drop-down menu next to CPU Usage Limit in the HD TDM Parameters section to change the amount of memory that Pro Tools will use. Pro Tools will allow you to allocate a maximum of 85% if your computer's processor has only one core.
- Change the number of RTAS processors. In the Playback Engine window, click on the drop-down menu next to “RTAS Processors” in the HD TDM Parameters section to change the number of processors that Pro Tools will use. The RTAS Processors option, when activated, will allow you to allocate more memory for Pro Tools using multiple cores on your processor. This setting works in tandem with the CPU utilization limit, allowing you to allocate up to 99% of the memory when working with multiple cores.
- Resize the hardware buffer. In the Playback Engine window, click the drop down menu next to Hardware Buffer Size in the HD TDM Parameters section to increase or decrease the buffer size. The large buffer size is ideal for editing and mixing processes, giving the computer more time to process audio and allowing it to work with large datasets. Smaller buffer sizes are recommended to reduce latency during recording.
- Resize the DAE buffer. In the Playback Engine window, click on the drop-down menu next to Size in the DAE Playback Buffer section to increase or decrease the buffer size. If you are experiencing lags during playback or recording, then setting the buffer to a smaller size can improve the speed of your computer. While a large buffer size can improve the performance of a task with a large number of edits, it can also increase time delays when starting playback and recording functions.