The WDM driver should shut down after a few minutes of silence. It won't shut down immediately as to not disrupt playback when you just pause briefly.
It seems to shut down after 3 seconds of silence here - which is short enough that if I seek during a YouTube video, it drops the connection.
It would be really nice if this was a preference we could set ourselves.
I understand the reasons why you might want it set to only 3 seconds, but I'd prefer to keep the connection open a lot longer than that.
EDIT: Sometimes this results in no audio being played until I seek again.
When doing a lot of testing to try and get audio in sync with video when using the WDM driver (which
was possible!) it seems that any
device buffer longer than 10ms is what causes the sound to "crackle" on my system when the WDM driver starts playback.
25ms occasionally does it, while 50ms+ always crackles at the start of playback.
This seems to be completely unrelated to the live playback latency setting.
Live Playback Latency seems to help prevent pops/clicks
during playback however.
But I need to keep that at the "minimum" setting to keep things in sync. (and the playback device at 5ms via WASAPI)
For my purposes, the WDM driver is mostly going to be used for streaming live video and processing the audio (e.g. adding dynamic range compression via the Adaptive Volume DSP) so it's more important that the audio is in sync than there being an occasional pop/click.
If I was using it for music, I'd keep the device buffer set to 10ms to eliminate the "crackle" when a track changes (though it may not be enough to avoid pops/clicks on some systems) and set the live input latency as high as possible.
As general tips for keeping latency down, don't enable any "unnecessary" DSPs.
Just having Output Format enabled was adding latency.
On my system at least, using it to resample was out of the question.
VST plug-ins may or may not add noticeable latency.
I'm able to keep Redline Monitor enabled as it adds <1ms latency.
Voxengo Elephant added 20-25ms latency.