WASAPI Exclusive: Push or Event?

[Starship Krupa]

This is one for @Noel Borthwick.

Does WASAPI Exclusive Event allow for lower latency (and/or jitter) than WASAPI Exclusive Push? Which method does Cakewalk use?

Conditional question: if Cakewalk only allows Push, might there be benefits latency-wise (and/or jitter-wise) to have the option in Sonar to use Event?

tl/dr:

I was messing about with my music player apps, which offer different options for WASAPI Exclusive, so I looked it up.

Event is said to offer lower latency on devices that support it (the DAC controls the flow of data, continuously "pulling" it from the app), and Push (where the app "pushes" it to the DAC) which is said to be more compatible with older devices but has higher latency.

Another aspect is jitter. Event relies on the clock in the interface for timing whereas Push relies on the computer's clock. Interface clocks are known to be more stable, and audio quality can suffer when there's more jitter.

This made me curious as to which of these Cakewalk uses, with the idea being if it uses Push, might having Event as an option for WASAPI Exclusive allow for lower latency (and/or jitter)?

Optional, 'cause we wouldn't want to break anything. It could be like Thread Scheduling Model. Only for use on systems that support it. It works a treat with my laptop's Realtek.

Edited September 12, 2023 by Starship Krupa

[Starship Krupa]

Okay, I Googled harder and found the answer to my own question. Cakewalk uses Event mode.

"WASAPI has four different modes of operation. SONAR supports WASAPI Exclusive mode using event signaling, because this mode is best suited for audio programs."

https://gaga.cakewalk.com/Documentation?product=SONAR X2&language=3&help=AudioPerformance.28.html

Oddly, the documentation for CbB changes this to:

"WASAPI has four different modes of operation. Cakewalk supports WASAPI Exclusive mode and WASAPI Shared mode."

https://legacy.cakewalk.com/Documentation?product=Cakewalk&language=3&help=AudioPerformance.29.html

This could be one for @Morten Saether.

Maybe it could say "Sonar supports two different modes of WASAPI operation, WASAPI Exclusive mode and WASAPI Shared mode. Sonar uses event signaling for WASAPI Exclusive mode, which is best for audio programs." Or something. It's not like it comes up very often....

(apologies to the "it's not possible for DAW's to sound different from each other" crew 😊)

[Noel Borthwick]

Cakewalk has supported event based WASAPI since 2008 when it came out.