lowlatency kernel status?

[Mike Holstein]

On Thu, Jan 27, 2011 at 12:03 PM, Scott Lavender
<scottalavender at gmail.com>wrote:

>
>
> On Thu, Jan 27, 2011 at 10:13 AM, Scott Lavender <scottalavender at gmail.com
> > wrote:
>
>> My experience is that the -lowlatency performs in a far superior manner
>> than the -generic one for audio work.
>>
>> Using my Dell P4, 2.8ghz machine with 3 gigs memory and an MAudio Delta 44
>> card I test the -generic kernel using JACK and Ardour and made test
>> recordings of guitar.  I found that the -generic kernel provided stable
>> performance (i.e. no xruns) at slightly over 22msecs.
>>
>> Using the same machine I installed Alessio's -lowlatency kernel and
>> testing it in the same manner.  I found that the -lowlatency kernel provided
>> stable performance (i.e. no xruns) at just under 3msecs.
>>
>> I hope all find this information useful.
>>
>> ScottL
>>
>>
>>
> I should point out that my the performance experienced with the -generic
> kernel suffered from not being able to have real-time privileges presumably
> due to the bug mentioned above.
>
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in lucid, i use the -realtime kernel with my firewire device regularly... i
have tested the -lowlatency kernel in both maverick and natty (more in
natty) and it seems i can actually push my JACK settings a little more... im
not positive this is happening, and there are more variables than kernel
involved, but the -lowlatency kernel in natty is at least as good
performance wise for me as lucid with -realtime... i use a presonus firepod,
and i test with JACK running around 1.2ms latency (not that i need it that
low usually)... the generic kernel is a no-go for me using firewire +
JACK... i have a pretty strict zero xrun policy, so i cant say i get less
xruns, i get 1 or 2 here or there opening an application, but not during
normal operation...

dont take my word for it though...

you can add abogani's ppa easily by reading
https://launchpad.net/~abogani/+archive/ppa

and running in a terminal

sudo add-apt-repository ppa:abogani/ppa

then, you can install both linux-realtime and/or linux/lowlatency in natty
and see how your hardware works... assuming this is a test install of natty
anyways, you are probably not worried about adding PPA's, but
http://ubuntu-tweak.com/ has a very nice and easy GUI way to purge PPA's and
the PPA's packages from the system that i have used in lucid...

IF you get a chance to test, let us know what you find and what hardware you
are testing with..

thanks




-- 
MH

http://opensourcemusician.libsyn.com/
http://wnclug.ourproject.org/
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