[PD] midi/latency

[oliver]

michael strohmann wrote:
> HI,
> what’s your strategies to reduce midi latency ?
> 
> in an installation setting i’m triggering samples from an e-drum (roland pad, millenium midi module) and the latency a get with the settigs below is 114 ms between trigger and sound.
> 
> delay(msec): 50 ms
> Block Size: 256
> 
> if i go any lower i get “resyncing audio” filling up the pd-window and occasional glitches up to a frozen pd…
> 
> occasionaly after a restart the latency is even closer to 250ms.
> 
> i am running this on a fairly decent gamer pc under windows 10 with the esi Gigaport HD+ audio interface

Hi, usually midi interfaces have little to no latencies, or at least 
they are most likely not your bottleneck. you have to use an ASIO driver 
to get real low latencies on windows systems, or ALSA on Linux. It won't 
work with the standard audio driver (MMIO).

For the Gigaport, i think there is an extra ASIO driver for download, 
but "usually" you will be better off with the ASIO4ALL driver (that 
would even work for your internal audiocard) - at least that's my 
experience with this soundcard on a windows machine.

Having said that, i'm not sure that the "Gigaport HD+" really supports 
low latencies at all. I used it once in an installation and remember 
that i had to use a higher amount of PD's audio delay (= soundcard 
buffer = overall latency) than with other soundcards, maybe a trade-off 
for the 8 channels.

Do you need all of them ? (I guess so ...)

Anyway, try the internal soundcard first and see how low you can get 
without hickups or clicks. to really test latencies i always use a test 
setup like this:

[0.5, 0 1000(
|
[line~]   [noise~]
|          |
[*~        ]
| \
[dac~]

where the midi trigger fires the message box. use your phone recorder to 
measure the "real life" latency between drum pad hit and noise woosh.

just for the record: i'm using a similar setup on an old acer netbook 
with UBUNTU and an old MAYA44USB card and getting very low latencies 
(less than 10ms) using ALSA drivers (PD blocksize 64, PD delay: 8)

i'm pretty sure that it's not your hardware that's lacking, but that you 
have to use a dedicated audio driver (ASIO or ALSA)



best

Oliver