Getting the most out of your computer

The maximum number of audio tracks you can expect to play on your computer depends on the audio sample rate, the speed of your hard disk, and the speed of your computer’s CPU.

The effect of your CPU on audio track throughput is much more difficult to quantify. Throughput is affected by the type of chip, clock speed, the number and type of real-time effects in use, cache size and settings, and many other factors.

There are a variety of things you can do to increase the number of audio tracks and effects you can play on your computer, as outlined in the following table.

Approach	How it works
Avoid compressed disks	If you use DoubleSpace, Stacker, or some other disk compression system, it will slow down playback of audio tremendously. Configure your system so that the Data directory is on a hard disk that is not compressed.
Exit other programs	The more programs you have open, the more CPU cycles you are taking away from your project. Exit any programs unnecessary to the task at hand.
Refrain from other activity during playback	If you open and close windows or do lots of editing while playback is in progress, you may steal CPU cycles that would otherwise be used for playback.
Apply some audio effects offline	If you are happy with your real-time effects, consider using the Process > Apply Effect > Audio Effects command to apply those effects offline. Then remove those effects from real-time use and free up lots of CPU power.
Archive unused audio tracks	Audio tracks that are muted continue to place a load on your processor. To lessen the burden and free up cycles to handle more audio, archive all unused audio tracks. See To archive or unarchive tracks for more information.
Mix down or freeze your audio/synth tracks	If your project contains many different audio/synth tracks or many real-time effects, you can use the Track view Tracks > Bounce to Track(s) command or click a track’s Freeze Track button to reduce all of this content to an audio track or tracks with no active effects.
Change I/O Buffer Size on the Advanced tab of the Audio Options dialog box	The default setting is 64 KB. Yours may work better with 128, 32, or 16. If those values don’t help, try 256, 512, or move on to another remedy.
Defragment your hard disk	If your hard disk is fragmented, playback of audio will be slower. Use the Disk Defragmenter to correct the situation.
Turn off dithering in the Edit > Preferences > Audio - Playback and Recording dialog box (choose None in the Dithering field).	Dithering subtly improves your mix, but most people can’t hear it. Turn it back on for mastering.
Enable read and write caching	By default, SONAR bypasses all disk caching, which typically results in better performance with audio data. If your computer has an older IDE disk controller, or a disk controller that does not use DMA transfers, enabling caching may improve SONAR's audio performance. Note: Changes to these settings only take effect when you restart SONAR. Go to Edit > Preferences > Audio - Sync and Caching to change the Enable Read Caching and Enable Write Caching settings.
Disable the Display Clip Contents options	Drawing the contents of audio clips in the Clips pane uses some CPU cycles. If you are using a slow machine, you may want to disable this feature. To do so, click the Track view View menu, point to Display and choose Display Clip Contents.

Digital audio files and storage

Digital audio requires a large amount of disk storage. The following table shows the disk space requirements in megabytes for a single minute of digital audio in mono and stereo at various sampling rates.

Sampling rate	16 bit	24 bit
11 kHz Mono	1.3 MB per minute	1.9 MB per minute
11 kHz Stereo	2.5 MB per minute	3.8 MB per minute
22 kHz Mono	2.8 MB per minute	3.8 MB per minute
22 kHz Stereo	5.0 MB per minute	7.6 MB per minute
44.1 kHz Mono	5.0 MB per minute	7.6 MB per minute
44.1 kHz Stereo	10.1 MB per minute	15.1 MB per minute
48 kHz Mono	5.5 MB per minute	7.6 MB per minute
48 kHz Stereo	11.0 MB per minute	16.5 MB per minute
96 kHz Mono	11.2 MB per minute	16.5 MB per minute
96 kHz Stereo	22.0 MB per minute	33.0 MB per minute

For more information, see Dropouts and other audio problems.

 

See:

Mixing latency

Queue buffers

CPU meter/Disk meter/Dropout indicator