I've been reading about WASAPI again. It uses something called Exclusive Mode and in my Win 10 under Sounds, it was checked by default.

There is little on the web newer than the big articles about this in 2015 where Pete Brown from MS (who is also a musician and DAW user) made tons of comments. His last post that I could find was Gearslutz in July 2015. He's talking about hardware developers have to write new drivers to take advantage of the new WASAPI but no mention of DAW's.

This is the newest blog post I could find under his username from Sept 2016 but it looks like word for word what he wrote in 2015:

https://www.reddit.com/r/Windows10/comments/50ty05/improved_audio_in_windows_10/

I also searched for DAW's that are configured to use WASAPI and found a bunch of them but no mention as to is that needed or not? I also found posts saying WDM is WASAPI just like MME is WDM. Since I have Studio One I checked it's config window and when I selected Windows Audio and go to the Control Panel for it I see a checkbox for Exclusive Mode and a slider for latency, it's set at 40ms as the default. Since Exclusive Mode is already set in Win 10 is that necessary to have in a DAW's config?

I tested this in RB:

In the Audio config window see Output Buffers. On my system the default is 2000. According to Help for that window that's supposed to be a two second delay but from what I can tell it's about a half second for both the notes displaying on the piano display using a midi file and the time my spacebar starts or stops playback. This is using a bluetooth QWERTY keyboard which has some delay as well. I took that all the way down to 30ms (tried 20 but a yellow box popped up saying that was out of range, the minimum is 30). RB played a 7 track midi file using ST3 along with 4 audio tracks without a glitch AND the notes displaying on the piano bar as well as my spacebar start/stop seems almost instantaneous. Sounds to me like RB using Win 10's new WASAPI.

Still, 30ms is not good enough for live playing of a softsynth plugin but it's a pretty major improvement anyway compared to WDM under Win 7. At least I can see what's happening on the screen with no visual delay.

I'm hardly an expert on this and my impressions could be wrong. Maybe Biab and RB do need a separate WASAPI driver but it doesn't seem like it. Getting 30-40 ms latency sounds about right based on what I read in those articles by Pete Brown. WASAPI is better but still not as good as ASIO.

Bob

Biab/RB latest build, Win 11 Pro, Ryzen 5 5600 G, 512 Gig SSD, 16 Gigs Ram, Steinberg UR22 MkII, Roland Sonic Cell, Kurzweil PC3, Hammond SK1, Korg PA3XPro, Garritan JABB, Hypercanvas, Sampletank 3, more.