Specifications

Getting Started with Mbox22
Configuring Pro Tools LE
Pro Tools System Settings
Pro Tools LE allows you to adjust the perfor-
mance of your system by changing system set-
tings that affect its capacity for processing, play-
back, and recording.
In most cases, the default settings for your sys-
tem provide optimum performance, but you
may want to adjust them to accommodate large
or processing-intensive Pro Tools sessions.
Hardware Buffer Size
The Hardware Buffer Size (H/W Buffer Size) con-
trols the size of the hardware cache used to han-
dle host processing tasks such as Real-Time Au-
dioSuite (RTAS) plug-ins.
◆ Lower Hardware Buffer Size settings improve
MIDI timing and automation accuracy, but limit
the number of RTAS plug-ins and mixer config-
urations you can run on your system
◆ Higher Hardware Buffer Size settings allow for
more audio processing and effects, and are use-
ful when you are using larger mixer configura-
tions or more RTAS plug-ins on your system.
To change the Hardware Buffer Size:
1 Choose Setups > Playback Engine.
2 From the H/W Buffer Size pop-up menu, select
the audio buffer size, in samples.
3 Click OK.
CPU Usage Limit
The CPU Usage Limit controls the percentage of
CPU resources allocated to Pro Tools host pro-
cessing tasks.
◆ Lower CPU Usage Limit settings limit the ef-
fect of Pro Tools processing on other CPU-inten-
sive tasks, such as screen redraws, and are useful
when you are experiencing slow system re-
sponse, or when running other applications at
the same time as Pro Tools.
◆ Higher CPU Usage Limit settings allocate
more processing power to Pro Tools, and are
useful for playing back large sessions or using
more real-time plug-ins.
◆ The maximum CPU Usage Limit is 85 percent
for single-processor computers, and 99 percent
for multi-processor computers. (The 99 percent
setting dedicates one entire processor to
Pro Tools.)
To change the CPU Usage Limit:
1 Choose Setups > Playback Engine.
2 From the CPU Usage Limit pop-up menu, se-
lect the percentage of CPU processing you want
to allocate to Pro Tools.
In addition to causing slower screen re-
sponse and monitoring latency, higher
Hardware Buffer Size settings can affect the
accuracy of plug-in automation, mute data,
and timing for MIDI tracks.
Playback Engine dialog for Mbox (Pro Tools 6.x)
Increasing the CPU Usage Limit may slow
down screen response on slower computers.