Florian Schmidt writes: Those results certainly are pretty poor. We do have a very similar test in the Rosegarden tree (the complainer test) but it doesn't stress the system quite the way it seems your program does. I'll have to review the sequencer API and look at adding a separate RT MIDI thread as an alternative (which should be straightforward enough). The rationale for using queued events is simple -- ALSA provides the service, why duplicate it? -- but it's probably true that we've already spent far more time working around problems with it than we saved by not duplicating it. (Does anyone else use queued sequencer events in earnest?) Chris