Reference Guide

1196 Improving audio performance
Improving performance with digital audio
Reduce GUI updates to improve playback performance
SONAR has a CPU conservation mode that reduces the number of GUI updates with no effect on
actual playback quality and rendering. This maximizes CPU resources for the audio engine and can
be useful while playing projects that consume a lot of CPU, to help avoid dropouts.
Like the Scroll Lock key, the Pause key now works as a special GUI throttle toggle key. When the
Pause key is pressed, SONAR runs in a CPU conservation mode by reducing the frequency of GUI
updates. For example, VU meter updates, Now position pointer and progress updates will appear to
update less frequently.
During CPU conservation mode, the UI is only updated once per second.
This mode can also be helpful to conserve CPU while doing a real-time bounce (see “Real-time
bounce” on page 923).
24-bit tips
Here are a few tips for playing back and/or recording at 24-bits:
• Try to play back at 24-bits even if your sound card only operates at 20- or 18-bits:
Having established the default settings for new files, you must also specify at what playback bit-
depth you want your sound card to use. In Edit > Preferences > Audio - Driver Settings , set
the Audio Driver Bit Depth to the desired value. Even if your sound card’s highest bit-depth is
only 18- or 20-bits, you should try selecting an Audio Driver Bit Depth of 24 first. If you receive
an error message when doing so, try selecting 20. If this also produces an error message, try
selecting 18. In other words, if you want SONAR to operate your sound card at any bit-depth
greater than 16-bits, try selecting the highest value possible in the Audio Driver Bit Depth
setting, and work downward from there if you have to.
(If your sound card’s maximum bit-depth is 20-bits and you specify an Audio Driver Bit Depth of
24 as advised above, audio data will still be sampled by your sound card in 20-bit samples, but
each sample will automatically be padded with extra 0’s to produce a 24-bit sample, which will be
stored at full 24-bit resolution in your project file.
• Some 24-bit cards require you to configure the order in which data is streamed:
If necessary, go to Edit > Preferences > Audio - Driver Settings and select one of the following
options in the Stream > 16-bit data as list:
• 3 bytes
• 4 bytes, right justified
• 4 bytes, left justified
• 32-bit PCM, right justified
• 32-bit PCM, left justfied
These settings affect how 24-bit audio samples are transferred from the sound card into the
SONAR software, and affect the efficiency of the transfer. You’ll get the best performance from
this card when working at 24-bits if you use the correct setting for your sound card. If you’re not
sure whether your particular sound card requires these settings, consult the documentation that