[LAU] xruns with m-audio fast track pro on fedora 8 ccrma ->kernel 2.6.22 , periods/buffer = 3 , proper rtirq setup, disable 2nd core

[Florent Berthaut]

Fernando Lopez-Lezcano a écrit :
> On Wed, 2008-01-23 at 16:44 +0100, Florent Berthaut wrote:
>   
>> Florent Berthaut a écrit : 
>>     
>>> Florent Berthaut a écrit : 
>>>       
>>>> Hartmut Noack a écrit : 
>>>>         
>>>>> -----BEGIN PGP SIGNED MESSAGE-----
>>>>> Hash: SHA1
>>>>> Florent Berthaut schrieb:
>>>>>           
>>>>>> Fernando Lopez-Lezcano a écrit :
>>>>>>     
>>>>>>             
>>>>>>> A more basic question... what parameters are you using when you start
>>>>>>> jackd?
>>>>>>>       
>>>>>>>               
>>>>>> .jackdrc:
>>>>>>
>>>>>> /usr/bin/jackd -R -P70 -t1000 -u -dalsa -r44100 -p64 -n2 -D -Chw:0,1 
>>>>>> -Phw:0,0 -S -i2 -o2
>>>>>>             
>>>>> USB-Devices often perform much better with -n3. Furthermore I would try
>>>>> to eliminate any flag, that is not absolutely needed such as:
>>>>>
>>>>> /usr/bin/jackd -R -dhw:1 -dalsa -r44100 -p64 -n3
>>>>>
>>>>> BTW: this would compute to around 4 ms latency - is that good enough for
>>>>> you?
>>>>>           
>>>> Okay, i had forgot to turn off the system "bips" and esd (it
>>>> reduced the number of xruns)
>>>> And yep with -n3 i 've got even less xruns and it seems they're
>>>> not audible. 
>>>> I don't know if the latency is low enough though, i'll test this
>>>> evening with my drum pads.
>>>>
>>>> Thanks everyone , it's really great to get so much help so
>>>> quickly. 
>>>>
>>>>         
>>> Argh, actually i still have audible xruns. And i don't think i'd be
>>> able to play correctly with a higher latency anyway...
>>> Think i'll have to get back to ubuntu studio ... :( 
>>>       
>> Actually after a reboot and some more tweakings, things have been
>> running without a xrun for an hour now, even with periods/buffer=2.
>>
>> So finally, i'll stay with planet ccrma ;) 
>>     
>
> You might want to try the 2.6.22.x based kernel for f8 as stated
> somewhere else in the thread. In my experience it has better performance
> latency-wise. 
>
> What other tweakings did you do?
>
> -- Fernando
>
>
>
>   

Ok finally, i tried to disable the second core ( i have a dual core 
2GHz) and things get really better this way, i can lauch more 
applications with 4,8ms latency and no xruns. I had already disabled 
cpuspeed but it looks like it was not enough.

Flo




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