[LAD] MidiSport vs. UA25

[Arnout Engelen]

I ran into a benchmark tool at http://github.com/koppi/alsa-midi-latency-test/
and ran it though my MidiSport 2x2 Anniversary Edition (no firmware upload 
required :) ) and Edirol UA-25EX.

Attached are the results on an untuned Debian Testing machine (2.6.30-1-686)
started with 'chrt -f 50 ./src/alsa-midi-latency-test -s 40'

The Edirol sure outperformed the MidiSport - the difference didn't seem huge
though.


(at the time of writing you need to add some symlinks to 
/usr/share/automake-1.10/... to make it build right, mailed the author about
that already).


Regards,

Arnout

On Thu, Sep 24, 2009 at 07:56:22AM -0400, Dave Phillips wrote:
> I've been experimenting with MIDI control from one machine to another. I 
> checked the timing of a single note played simultanesouly by instances 
> of QSynth on both machines and was surprised to hear a very noticeable 
> flamming. I then replaced the MidiSport 2x2 with my Edirol UA25 and the 
> flamming disappeared. Both are USB interfaces, btw. MIDI routing between 
> the machines is handled by a Yamaha MJC8 and has never been problematic 
> with that box.
> 
> So, my question(s): Is the MidiSport just poorly designed and is there a 
> further condition or module option that can correct the timing delay 
> from that unit ?
> 
> Best,
> 
> dp
> 
> _______________________________________________
> Linux-audio-dev mailing list
> Linux-audio-dev at lists.linuxaudio.org
> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
-------------- next part --------------
rnouten at bird:~/progs/alsa-midi-latency-test$ chrt -f 50 ./src/alsa-midi-latency-test -s 40 --input 28:0 --output 28:0
> calibrating high precision timer loop.. done.
time diff =                           0.00
loops/sec =            8661432571218325.00

> sampling 10000 midi latency values - please wait..
> press Ctrl+C to abort test.
> skipping first 40 latency samples.

sample; latency_ms; latency_ms_worst
    41;       2.30;       2.30     
    42;       2.78;       2.78     
    43;       2.81;       2.81     
   165;       2.85;       2.85     
   166;       2.86;       2.86     
   167;       2.91;       2.91     
   567;       2.93;       2.93     
   666;       2.93;       2.93     
   667;       2.97;       2.97     
  1110;       3.17;       3.17     
  2581;       3.41;       3.41     
  2582;       3.59;       3.59     
 10000;       2.26;       3.59     
> done.

> latency distribution:
...
  1.1 -  1.2 ms:        7 #
...
  1.5 -  1.6 ms:        2 #
  1.6 -  1.7 ms:        8 #
  1.7 -  1.8 ms:       37 #
  1.8 -  1.9 ms:       12 #
  1.9 -  2.0 ms:        6 #
  2.0 -  2.1 ms:       11 #
  2.1 -  2.2 ms:       10 #
  2.2 -  2.3 ms:     7131 ###################################################
  2.3 -  2.4 ms:     2114 ###############
  2.4 -  2.5 ms:       74 #
  2.5 -  2.6 ms:      345 ###
  2.6 -  2.7 ms:      172 ##
  2.7 -  2.8 ms:       26 #
  2.8 -  2.9 ms:       16 #
  2.9 -  3.0 ms:       21 #
...
  3.1 -  3.2 ms:        1 #
  3.2 -  3.3 ms:        2 #
...
  3.4 -  3.5 ms:        2 #
  3.5 -  3.6 ms:        1 #

-------------- next part --------------
arnouten at bird:~/progs/alsa-midi-latency-test$ chrt -f 50 ./src/alsa-midi-latency-test -s 40 --input 24:0 --output 24:0
> calibrating high precision timer loop.. done.
time diff =                           0.00
loops/sec =            8661432571218325.00

> sampling 10000 midi latency values - please wait..
> press Ctrl+C to abort test.
> skipping first 40 latency samples.

sample; latency_ms; latency_ms_worst
    41;       2.82;       2.82     
    42;       3.37;       3.37     
    72;       3.51;       3.51     
   316;       3.63;       3.63     
  1520;       3.69;       3.69     
  3927;       3.72;       3.72     
  4133;       4.55;       4.55     
 10000;       2.93;       4.55     
> done.

> latency distribution:
...
  1.8 -  1.9 ms:        1 #
...
  2.2 -  2.3 ms:       73 #
  2.3 -  2.4 ms:       63 #
  2.4 -  2.5 ms:       15 #
  2.5 -  2.6 ms:        9 #
  2.6 -  2.7 ms:       13 #
  2.7 -  2.8 ms:        4 #
  2.8 -  2.9 ms:     8496 ###################################################
  2.9 -  3.0 ms:      687 #####
  3.0 -  3.1 ms:      172 ##
  3.1 -  3.2 ms:      262 ##
  3.2 -  3.3 ms:      158 #
  3.3 -  3.4 ms:        7 #
  3.4 -  3.5 ms:        9 #
  3.5 -  3.6 ms:       11 #
  3.6 -  3.7 ms:       12 #
  3.7 -  3.8 ms:        4 #
...
  4.1 -  4.2 ms:        1 #
...
  4.5 -  4.6 ms:        1 #