If you experience problems in real-time audio on Windows, you should definitely analyze what is going on with one or both of these tools:
- LatencyMon : http://www.resplendence.com/latencymon
- DPC latency checker: https://www.thesycon.de/eng/latency_check.shtml (alternate: https://www.softpedia.com/get/System/System-Info/DPC-Latency-Checker.shtml)
If the SOUND4 Stream has troubles like timeouts, you may try to increase its priority:
Open Regedit and go to Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SOUND4 Stream and add --priority high to the Parameters key.
For the SOUND4 watermark, default priority is realtime (rt). It can be lowered the same way with high, normal or low.