An excellent Audio Performance Benchmark Sound Music AC97 in FamiTracker 0.4.6

We all know it: Choppy audio playback in VBox with AC97 driver from rapps.
I found an excellent benchmark for that: The application Fami-Tracker 0.4.6 from rapps.

Out of the box it uses an audio buffer of 40ms, which gives me very choppy audio playback on my Pentium E5200 @ 2x2300MHz without VT-x in VBox 4.3.12.

Observed result
0.4.14-RC-98-gc437ff6 gcc 4.7.2 dbg currently manages
The default of 40ms buffer gives choppy output. (and even informs about the lost samples in the apps status bar, although CPU usage is not maxed out yet)
As soon as I increase the buffer from 40ms to at least 61ms/62ms, I can listen for the music without any distortions for > 1minute. Perfect playback.
60ms buffer gives the first single distortions within the first 10seconds already.

Contrary when I use the same app on same host, in same virtualization with the same driver in Win2k3sp2, it plays fluid audio at 40ms default already, and I can go all the way down to the minimum of 1ms even and the sound-playback is still fluid.

Expected result
The request and the "DefinitionOfDone" of this ticket is to speed up the audio stack of ReactOS to give fluent playback with the default 40ms at least on my PC. That would then still be at least 40times lower performance compared to 2k3sp2, but there must be a goal to allow resolving this ticket. So as soon as we manage to reach fluent playback with 40ms on my PC, we are done with this ticket.

I do expect a lot of applications to benefit from that ofc, FamiTracker is just a benchmark here

Reproduction steps

• Watch the video for instructions what music to play and how to adjust the buffer
• 0.4.14-RC-98-gc437ff6_AudioBench.webm what to do
• 0.4.14-RC-98-gc437ff6_AudioBench.log is not interesting, just added for following the rules
• Close all other apps in ros while performing the benchmark