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Jakob Flierl edited this page Aug 2, 2015 · 1 revision
$ cat /etc/*release*
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=9.10
DISTRIB_CODENAME=karmic
DISTRIB_DESCRIPTION="Ubuntu 9.10"
$ uname -r
2.6.31-9-rt
$ lspci |grep -i audio
05:01.0 Multimedia audio controller: VIA Technologies Inc. ICE1712 [Envy24] PCI Multi-Channel I/O Controller (rev 02)

$ cat /proc/asound/cards
 1 [M2496          ]: ICE1712 - M Audio Audiophile 24/96
                      M Audio Audiophile 24/96 at 0xbc00, irq 22
$ alsa-midi-latency-test -l
 Port    Client name                      Port name
 20:0    M Audio Audiophile 24/96         M Audio Audiophile 24/96 MIDI
128:0    TiMidity                         TiMidity port 0
128:1    TiMidity                         TiMidity port 1
128:2    TiMidity                         TiMidity port 2
128:3    TiMidity                         TiMidity port 3

$ alsa-midi-latency-test -i 20:0 -o 20:0
> alsa-midi-latency-test 0.0.3
> clock resolution: 0.000000001 s

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

sample; latency_ms; latency_ms_worst
     0;       1.01;       1.01     
   144;       1.20;       1.20     
  1615;       1.25;       1.25     
  2515;       1.36;       1.36     
  2965;       1.66;       1.66     
  9999;       0.98;       1.66     
> done.

> latency distribution:
...
  1.0 -  1.1 ms:     9967 ##################################################
  1.1 -  1.2 ms:       15 #
  1.2 -  1.3 ms:       10 #
  1.3 -  1.4 ms:        1 #
  1.4 -  1.5 ms:        5 #
  1.5 -  1.6 ms:        1 #
...
  1.7 -  1.8 ms:        1 #

> SUCCESS

 best latency was 0.97 ms
 worst latency was 1.66 ms, which is great.

$ alsa-midi-latency-test -i 20:0 -o 20:0
> alsa-midi-latency-test 0.0.3
> clock resolution: 0.000000001 s

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

sample; latency_ms; latency_ms_worst
     0;       1.01;       1.01     
   204;       1.49;       1.49     
  1955;       1.62;       1.62     
  2966;       1.96;       1.96     
  3979;       2.11;       2.11     
  9999;       0.98;       2.11     
> done.

> latency distribution:
...
  1.0 -  1.1 ms:     9961 ##################################################
  1.1 -  1.2 ms:       19 #
  1.2 -  1.3 ms:        8 #
  1.3 -  1.4 ms:        3 #
  1.4 -  1.5 ms:        4 #
  1.5 -  1.6 ms:        2 #
  1.6 -  1.7 ms:        1 #
...
  2.0 -  2.1 ms:        1 #
  2.1 -  2.2 ms:        1 #

> SUCCESS

 best latency was 0.97 ms
 worst latency was 2.11 ms, which is great.

$ alsa-midi-latency-test -i 20:0 -o 20:0
> alsa-midi-latency-test 0.0.3
> clock resolution: 0.000000001 s

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

sample; latency_ms; latency_ms_worst
     0;       1.02;       1.02     
    23;       1.55;       1.55     
  2157;     timeout: there seems to be no connection between ports 20:0 and 20:0

$ alsa-midi-latency-test -i 20:0 -o 20:0
> alsa-midi-latency-test 0.0.3
> clock resolution: 0.000000001 s

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

sample; latency_ms; latency_ms_worst
     0;       1.01;       1.01     
     4;       1.05;       1.05     
   805;       1.13;       1.13     
   863;       1.22;       1.22     
  1072;       1.72;       1.72     
  9999;       0.98;       1.72     
> done.

> latency distribution:
...
  1.0 -  1.1 ms:     9952 ##################################################
  1.1 -  1.2 ms:       20 #
  1.2 -  1.3 ms:       14 #
  1.3 -  1.4 ms:        4 #
  1.4 -  1.5 ms:        4 #
  1.5 -  1.6 ms:        3 #
  1.6 -  1.7 ms:        2 #
  1.7 -  1.8 ms:        1 #

> SUCCESS

 best latency was 0.97 ms
 worst latency was 1.72 ms, which is great.

$ alsa-midi-latency-test -i 20:0 -o 20:0
> alsa-midi-latency-test 0.0.3
> clock resolution: 0.000000001 s

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

sample; latency_ms; latency_ms_worst
     0;       1.02;       1.02     
   114;       1.18;       1.18     
   534;       1.34;       1.34     
  1885;       1.37;       1.37     
  2514;       1.63;       1.63     
  9999;       0.99;       1.63     
> done.

> latency distribution:
...
  1.0 -  1.1 ms:     9959 ##################################################
  1.1 -  1.2 ms:       19 #
  1.2 -  1.3 ms:       11 #
  1.3 -  1.4 ms:        4 #
  1.4 -  1.5 ms:        4 #
  1.5 -  1.6 ms:        2 #
  1.6 -  1.7 ms:        1 #

> SUCCESS

 best latency was 0.97 ms
 worst latency was 1.63 ms, which is great.

$ alsa-midi-latency-test -R -i 20:0 -o 20:0
> alsa-midi-latency-test 0.0.3
> set_realtime_priority(SCHED_FIFO, 99).. done.
> clock resolution: 0.000000001 s

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

sample; latency_ms; latency_ms_worst
     0;       1.02;       1.02     
  6946;       1.02;       1.02     
  6947;       1.03;       1.03     
  9999;       0.98;       1.03     
> done.

> latency distribution:
...
  1.0 -  1.1 ms:    10000 ##################################################

> SUCCESS

 best latency was 0.97 ms
 worst latency was 1.03 ms, which is great.

$ alsa-midi-latency-test -R -i 20:0 -o 20:0
> alsa-midi-latency-test 0.0.3
> set_realtime_priority(SCHED_FIFO, 99).. done.
> clock resolution: 0.000000001 s

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

sample; latency_ms; latency_ms_worst
     0;       1.01;       1.01     
    27;       1.04;       1.04     
  9999;       0.98;       1.04     
> done.

> latency distribution:
...
  1.0 -  1.1 ms:    10000 ##################################################

> SUCCESS

 best latency was 0.97 ms
 worst latency was 1.04 ms, which is great.