DigiDesign DigiRack, Manual

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Chapter 3: Working with Real-Time Plug-ins 11
RTAS Processors
The RTAS Processors setting determines the
number of processors in your computer allo-
cated for RTAS plug-in processing.
With computers that have multiple processors,
or that feature multi-core processing or hyper-
threading, this setting lets you enable multi-pro-
cessor support for RTAS processes. Used in com-
bination with the CPU Usage Limit setting, the
RTAS Processors setting lets you control the way
RTAS processing and other Pro Tools tasks are
carried out by the system.
◆ A higher number of processors reserves more
CPU processing capacity for RTAS plug-in pro-
cessing. This is useful for sessions with large
number of RTAS plug-ins.
◆ A lower number of processors leaves more
CPU processing capacity for automation, screen
redraws, and video playback in Pro Tools, or for
other application running at the same time as
Pro Tools.
To set the number of RTAS Processors:
1
Choose Setup > Playback Engine.
2
From the RTAS Processors pop-up menu, select
the number of available processors you want to
allocate for RTAS plug-in processing.
3
Click OK.
CPU Usage Limit
The CPU Usage Limit controls the percentage of
CPU resources allocated to Pro Tools host pro-
cessing tasks such as RTAS plug-in performance
and screen redraws.
◆ 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.
To change the CPU Usage Limit:
1
Choose Setup > 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. (On dual-processor Mac
computers, this setting controls the allocation
of a single processor.)
3
Click OK.
Increasing the CPU Usage Limit may slow
down screen response on slower computers.
For more information on the Hardware
Buffer Size and CPU Usage Limit, refer to
the
Pro Tools Reference Guide .