CHAPTER 29. COMPUTER AUDIO RESOURCES AND STRATEGIES
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29.1.2
CPU Load from Tracks and Devices
Generally, every track and device being used in Live incurs some amount of CPU load.
However, Live is smart and avoids wasting CPU cycles on tracks and devices that do not
contribute anything useful.
For example, dragging devices into a Live Set that is not running does not signi cantly
increase the CPU load. The load increases only as you start playing clips or feed audio into
the effects. When there is no incoming audio, the effects are deactivated until they are
needed again. (If the effect produces a tail, like reverbs and delays, deactivation occurs
only after all calculations are complete.)
While this scheme is very effective at reducing the average CPU load of a Live Set, it cannot
reduce the peak load. To make sure your Live Set plays back continuously, even under
the most intense conditions, play back a clip in every track simultaneously, with all devices
enabled.
29.1.3
Track Freeze
Live's Freeze Track command can greatly help in managing the CPU load incurred by devices
and clip settings. When you select a track and execute the Freeze Track command, Live
will create a sample le for each Session clip in the track, plus one for the Arrangement.
Thereafter, clips in the track will simply play back their freeze les rather than repeatedly
calculating processor-intensive device and clip settings in real time. The Freeze Track
command is available from Live's Edit menu and from the
(PC) /
Ctrl
(Mac) context
menu of tracks and clips. Be aware that it is not possible to freeze a
Group Track
; you can
only freeze tracks that hold clips.
Normally, freezing happens very quickly. But if you freeze a track that contains an
External
Audio Effect
or
External Instrument
that routes to a hardware effects device or synthesizer,
the freezing process happens in real-time. Live will automatically detect if real-time freezing
is necessary, and you'll be presented with several options for managing the process. Please
see the section on
real-time rendering
for an explanation of these options.
Once any processing demands have been addressed (or you have upgraded your machine!),
you can always select a frozen track and choose Unfreeze Track from the Edit menu to change
