Setup guide

Pro Tools|HD Setup Guide102
Monitoring DSP Usage
The System Usage window provides a display of
DSP usage. With these indicators as your guide,
you can try different mixer setups and different
arrangements of plug-ins, sends, and Auxiliary
Inputs to maximize your use of available DSP
power.
Pro Tools HD also maintains a Plug-in and Mixer
cache for allocated DSP when closing and open-
ing sessions. While this does not change the
time it takes to open the first session after you
launch Pro Tools, it does result in being able to
open and close all subsequent Pro Tools sessions
quickly, especially when using the Revert To
Saved command or when opening similarly con-
figured sessions.
As long as Pro Tools is running, the DSPs will
only be completely purged if you open a session
with a different sample rate or one with differ-
ent Playback Engine settings.
About Processing Bandwidth
Meters in the System Usage window indicate
how much of your system’s processing power is
being used in processing audio, and when writ-
ing and playing back automation.
As these meters approach their limits, native
processing and recording, or playback of auto-
mation data can be affected. If CPU or PCI Activ-
ity are high, a system error may occur. If Disk
Activity is high, Pro Tools may miss playback of
some automation data during particularly dense
periods of activity, such as while using the
Bounce to Disk command.
System Activity Meters
PCI Displays the amount of PCI bus activity.
CPU (RTAS) Displays the amount of CPU pro-
cessing activity for RTAS processing.
CPU (Elastic) Displays the amount of processing
activity for Real-Time Elastic Audio processing.
Disk Displays the amount of hard disk process-
ing activity.
Additional Meters
TDM Voices Allocated Displays the total num-
ber
of TDM voices that can be allocated and the
number of voices currently allocated. This in-
cludes all voices whether they are allocated
explicitly or dynamically, as well as any voices
used for routing RTAS processing.
TDM Time Slots Used Displays the total number
of TDM Time Slots available and the number of
TDM Time Slots currently used.
DSP Usage (Accel Core, HD Core, HD Accel, and
HD Process) Displays the percentage of how
much of each DSP chip on each Pro Tools|HD
card is currently being used for mixer configura-
tions and TDM plug-ins.
To monitor the usage of DSP resources during a
Pro Tools session:
 Choose Window > System Usage.
System Usage window
DSP
Usage
System
Activity
TDM
DSP
Cache