Specifications

Pro Tools Reference Guide598
Each chip on a card can only power a certain
number of processing functions. If you have a
single HD card, MIX card or DSP Farm card, and
you create a big enough TDM mixer and use
enough sends or plug-ins, you will eventually
use up or “max out” all DSPs.
HD Accel Cards and DSP
Each HD Accel card includes nine DSP chips:
◆ Seven of the chips on HD Accel cards are
220 MHz Motorola DSP chips, which are more
than twice as fast as the chips on HD Process
cards. These chips are provided in the following
two memory configurations:
• Four of the seven chips are configured with
512k of external SRAM to accommodate
long delays and reverbs, even at 88.2 kHz
and higher sample rates.
• The remaining three chips provide 160k of
internal memory, capable of supporting a
wide variety of plug-ins with more in-
stances than previously available.
◆ Two chips are original Pro Tools|HD-series
DSP chips. These chips are used for mixers and
plug-ins.
Mixing and DSP Usage
Pro Tools builds a TDM mixer every time a ses-
sion is opened. Note that the term “mixer chan-
nel” applies to audio tracks (total voiceable
tracks) and Auxiliary Input tracks, as well as
sends and returns that use any of the 64 TDM
internal busses. When you go beyond a certain
number of mixer channels, Pro Tools will use
another DSP to create additional mixer capacity.
Master Faders do not use additional DSP power.
With Pro Tools|24 systems, Pro Tools does not
always automatically free up all unused DSP
power when you delete an unneeded mixer
channel. On these systems, to reclaim all DSP
power after a change in your session configura-
tion, close your session and reopen it. Pro Tools
will rebuild your new mixer configuration to use
DSP power with maximum efficiency.
DSP Manager
(TDM Systems Only)
Pro Tools software (version 4.3 and higher) in-
cludes DSP Manager, a software component that
optimizes the use of DSP capacity on
Pro Tools HD-series and MIX-series systems.
When you have an HD (or MIX) card in your
system, if your current DSP usage is approaching
the capacity of the card, and you then try to add
a mixer channel or assign a plug-in, the DSP
Manager will automatically try to make room
for the new mixer or plug-in on the HD (or MIX)
card. It does this by reallocating the existing
TDM mixers and plug-ins to use the available
DSP capacity on the HD (or MIX) card as effi-
ciently as possible.
Monitoring DSP Usage
The System Usage window provides a display of
DSP usage. As you allocate DSP to mixing or pro-
cessing with plug-ins, the System Usage window
indicates when DSP chips are available and
when they are in use. Green indicates a chip is
free. Red indicates a chip is in use.
There are three different System Usage view for-
mats: Large, Detailed, and Gas Gauge. The De-
tailed and Gas Gauge formats show the percent-
age of each DSP chip in use.