[linux-audio-user] es1370 latency and jackd, late driver wakeup

[Louis Lam]

Hello All,

I have a bunch of old consumer sound cards. SBLive, Vibra128 and ensoniq 1370(es1370). I went
through quite a number of rounds trying out these cards and found that IMHO the es1370 gave me the
best sound amongst these cards. So i went ahead and try to start jack according to the
capabilities of this card.

With this card, i find that once i start jackd like this:

jackd -v -R -d alsa es1370 -r 44100 

I get lots of xruns immediately.

Then i tried with the n=4 (ie 4 periods per hardware buffer), i.e "jackd -v -R -d alsa es1370 -n
4" and I am able to get rid of the xruns. But i see lots of "late driver wakeup: nframes to
process=2048" on the jackd output. What does this message mean? 

For recording into ardour, n=4 and the default frames per period (1024) gives me quite significant
latency when recording. e.g when I pluck a note on the electric bass i can hear it on the line-in
monitor first and then from the capture slightly later.

As a compromise, i set the frames per period to either 64, 128 or 256. But I still get  the "late
driver wakeup" message and occasional xrun when i quit ardour or sometimes even hydrogen. I notice
that when quitting jackd programs there will sometimes be a few xruns. Is this normal?

Seems like ideal to start n=2 but this card don't seem to allow me to do that. I could be wrong
but i think for low latency n=2 is ideal. 

If i have saved an ardour project with Tim Goetze's plugin activated in some tracks, ardour may
report that it is too slow or (something like that) when i reload that project file. I suspect
this is to do with some ladspa plugins requiring low latency which my setup is not able to give.

I know this card is old, but it does give a great sound. I used SBLive previously and don't seem
to have these latency issues (able to start jack with n=2). For owners of this card, any sound
advice to get the most out of it?



Thank You very much,
Louis



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