A question about the audio buffer and stuttering audio

[roondar]

I've recently been having some problems with the audio output of WinUAE. During some games and applications, audio sometimes starts to produce audible 'clicks'/'stutters' (difficult to describe really).

The first time I noticed it was when I ran PowerGlove, which had perfect audio on my real A500, but had the problem I described above. I tried running it on a variety of different configurations and eventually found that using an A500 type config, disabling cycle exact mode and disabling the 'more compatible' flag on the processor tab seemed to help - though even then I still needed an audio buffer size of 9 for it to be stable.

I noticed it again during development when I started adding audio, sometimes the audio would seemingly underrun the buffer. The situation does seem to improve if I select WSAPI instead of DirectSound but it still occasionally happens. I've even run LatencyMon, which claims my system should be fine for 'real time audio'.

Main difference since I started noticing this problem was that I upgraded WinUAE from a rather old version (3.2 I think) to the most recent one at the time (4.1).

I'm a bit puzzled by this problem as I have a fairly fast CPU (Intel i7 3770@3.4GHz) and a SoundblasterX AE-5 which never seems to have any problems. I'm not running WinUAE while also running a bunch of heavy applications and the task manager seems to suggest that overall system load and individual CPU cores are all well within limits.

However, I can't be certain what causes this - I can't rule out it's not WinUAE (which usually works really well). But just to try and rule that out: what settings should I try to get the best results for audio?

Any help would be greatly appreciated!

[Toni Wilen]

It is practically never anything to do with sound emulation or hardware.
Most common causes are:
- aggressive power saving (approximate/cycle-exact modes use physical CPU time in very short bursts. Test if fastest possible CPU makes any difference)
- display rendering being too slow (forced vsync etc..). Check if windowed mode/fullscreen/D3D9/D3d11 changes make any difference.
- too slow CPU (not in this case, unless it is overheating and throttling)

AE-5 is good, it also supports quite low buffer sizes.

[roondar]

Thanks for the tips, I'll try them out. I'm pretty certain the CPU isn't throttling, but I'll check anyway.

I may have forced VSYNC on so that's a good thing to try. And I didn't know that WinUAE had different D3D options so I'll check that out to.

Would changing WinUAE priority potentially help?

[Toni Wilen]

Originally Posted by roondar

I may have forced VSYNC on so that's a good thing to try. And I didn't know that WinUAE had different D3D options so I'll check that out to.

Winuae won't like externally forced vsync.

Would changing WinUAE priority potentially help?

No