On Mon, 2010-07-05 at 09:16 +0200, Clemens Ladisch wrote: > Niels Mayer wrote: > > Here's the new results with "-w 20" (nb: "-w" == "-w 0") > > > >> A) Edirol UM-2 > > > > best latency was 2.07 ms > > worst latency was 3.11 ms, which is great. > > As long we're optimizing for benchmarks: In recent enough kernel > versions, Roland (Edirol/BOSS) USB MIDI devices have a mixer control > "MIDI Input Mode" (the same as the "Light Load" checkbox in the Windows > driver) which doesn't have much effect in practice but can improve > benchmark behaviour. > > For bulk transfers (used by Roland devices in "High Load" mode, and > always by all other devices), the UHCI driver has a feature called FSBR > (full-speed bandwidth reclamation) which makes the controller poll the > device continuously instead of every 1 ms, as long as new input is > available every 10 ms. So to get better benchmark numbers, use "-w 1" > instead of "-w 20". (If your music doesn't have new notes every 10 ms, > this isn't very realistic, but it can improve latency between the > consecutive notes of a chord.) > > > Regards, > Clemens
I noticed that I run my test without the "-R" switch "alsa-midi-latency-test -i20:0 -o20:0" and Gustin who already used "-w 20 -r" did also miss the "-R" switch, "alsa-midi-latency-test -i 16:0 -o 16:0 -w 20 -r". alsa-midi-latency-test --help -R, --realtime use realtime scheduling (default: no) Did you add "-R"? Cheers! Ralf _______________________________________________ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev