Hi! I need help with understanding what “Time Load” is.
I had problems with crackling audio - initially caused by the Wavestate Native, and the quirks of Kontakt Player. These were resolved, but I still got crackles whenever Time Load went much above 100%. I presumed that it was because I was using all or all of the 16GBits of RAM. I have now upgraded to 32GBits, but the issue remains. Any suggestions, guys?
DAWs process audio in cycles, where a cycle’s duration is defined by your buffer size and sample rate in your audio engine settings. For example, if you have your buffer size set to 256 and your sample rate set to 44100 Hz, then your cycle duration will be about 256/44100 = 5.8ms. That means that Cantabile has at most 5.8ms to receive each 256-sample buffer of audio data from all your plugins. If your plugins don’t respond within that time, you get crackling because Cantabile has no audio data to send to your audio drivers for that cycle.
The “Time Load” is basically the percentage of the cycle duration that your plugins are actually consuming. So if your time load is 50%, then you’re fine because your plugins are only taking up half the allotted time. But if you’re over 100%, your plugins can’t keep up.
Time load is affected by many things; it’s not merely the sum of the times consumed by all the plugins. For example, depending on your cpu capabilities, your audio settings, and how you have your plugins wired together, Cantabile can ask some of your plugins to process their data in parallel during each cycle. But if plugin A receives output from plugin B, then plugin A needs to completely finish before plugin B can start its processing. Exceeding your RAM can also play a role, since that requires your OS to spend time swapping data to/from disk during the cycle, consuming yet more precious time.
Many thanks, Hamlen. That is very helpful. I will experiment with different buffer sizes and see how I get on.
Many who struggle with strangely high time loads eventually discover that some other process or background service is the real problem, so I advise looking at everything you have installed.
For example, I once had persistent crackling until I uninstalled a certain graphics driver. It didn’t appear in the Task Manager, exhibited no significant CPU or memory usage, and was basically invisible. But it quietly used .NET services to monitor system activity in the background, which slowed Cantabile’s access to .NET services, preventing it from keeping up with the audio cycle. Replacing it with the bare-bones Windows display driver fixed it.
I assume that you have followed Brad’s optimizing guide. Unfortunately, much of that has to be done. Also, to find runaway tasks there is Latency Monitor 7.31:
There are several drivers that commonly cause problems, plus things like ACPI.sys. Look in Brad’s guide about disabling devices.
Good luck John
Thanks John. Yes I have followed Brad’s guide, and as I said earlier I need to explore buffer sizes.
I am running an i7 2.8GHz processor, and am using a Steinberg USB driver set to low latency and a 513 Samples buffer size. Latencies are 15.692 ms (input) and 18.685 ms (output).
Having doubled the RAM size, maybe I can now increase the buffer size as well.
Hi David,
given the specs of your system and since you have followed Brad’s guide, it seems strange to me that you are still experiencing cracklings and large Time Loads. Increasing the buffer size beyond 512 samples will also increase the latency and it could become too large (expecially when playing fast passages with a fast attack sound).
You could check if the large load is due to some particular plugin by opening the “Profiler” (View->Profiler).
The bottom row of the profiler shows the time load value as vertical bars (one bar for each second, if I remember well). You can click on the pause button to stop it, so that you can examine it (even clicking on a bar should pause it). When the Time Load is larger than 100% the bar should become red. The top panel shows the peak and average Time Load and also the contribution of each plugin to the Time Load. By clicking on a bar, you can see how much each plugin is contributing and possibly find the culprit.
Good luck,
Gabriel
Many thanks, Gabriel.
I have followed the various pieces of advice, and then tested various different buffer sizes, actually making very little difference.
I am grateful for you pointing me to the Profiler, which has exposed some of my vst libraries as the probable causes. One is Spitfire Audio’s Cinematic Pads, which seems to be very resource hungry, along with instances of Kontakt Player. This is going to prove very helpful as I rationalise my use of vsts to reduce loads.
Thanks to all who have helped out!