Understanding Cantabile's Performance Metrics

Time Load

Cantabile's time load display is a measure of how long it takes to process one audio cycle. It's calculated as a fraction of the length of the audio buffer.

eg: if you audio buffer is configured to be 10ms and it takes 4ms to process the audio cycle, load will be reported as 40%.

Cantabile displays the maximum load of all audio cycles in the previous 1 second.

Note that this is a measure of processing time, not CPU load - which are quite different things. It's possible for time load to be high but CPU usage to be low. For example, reading data from disk is slow and takes time but CPU usage is low (since it's just waiting). Cantabile also displays CPU load metrics however these are less useful for assessing real-time audio performance.

With a well written host and plugins, CPU load and Time load should correlate - but are measured in very different ways and can not be compared.

Sometimes it's possible for load to exceed 100% without audio drop outs. This can happen if one audio cycle is stalled but the average is still well below 100%. In this case additional audio driver buffering can compensate for the one slow cycle. If however load is continuously, or excessively above 100% audio drop outs will result.