DigiDesign DigiRack, Manual

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Chapter 3: Working with Real-Time Plug-ins 9
chapter 3
Working with Real-Time Plug-ins
Real-time plug-ins process audio nondestruc-
tively in real time. They do not alter the original
source audio, but only apply their effect during
playback.
There are two formats of real-time plug-ins:
TDM Plug-ins
Rely on the processing power of
Digidesign DSP cards. TDM plug-ins run only on
Pro Tools|HD systems.
RTAS Plug-ins
Rely on the processing power of
your computer. RTAS plug-ins run on
Pro Tools|HD and LE systems.
Processing Power
Requirements of TDM and
RTAS Plug-ins
TDM and RTAS plug-ins differ in their process-
ing power requirements.
TDM Plug-ins
Each real-time TDM plug-in that is inserted in a
Pro Tools session uses a portion of your system’s
total available DSP resources.
Since these DSP resources reside on the cards
that make up your particular Pro Tools hard-
ware configuration, the amount of DSP avail-
able depends entirely on the number and type
of DSP cards in your system.
You can add more mixing and processing power
to your system by installing additional DSP
cards, provided you have unused PCI (or PCIe)
expansion slots in your computer or use a
Digidesign-approved Expansion Chassis.
The System Usage window (Window > System
Usage) shows how much DSP is available on
your system, and gives an approximation of
how it is currently being used.
For more information on the System Usage
window, see the
Pro Tools Reference Guide .
System Usage window
See Appendix A, “DSP Requirements for
TDM Plug-ins” for relative numbers of in-
stances of each DigiRack TDM plug-in that
can be powered by a single DSP chip. DSP
capacity differs with card type.