[PlanetCCRMA] Reliable version of Fedora using rt-kernel?

Fernando Lopez-Lezcano nando at ccrma.Stanford.EDU
Sun Nov 13 15:23:51 PST 2011

On 11/13/2011 12:05 PM, John S. Dey wrote:
> Hi Fernando,
> Thanks for getting back to me. No. You're presumption was incorrect. I
> hadn't install rtirq. I have now but it didn't make much different.

(it does not necessarily make a difference, basically it tries to give 
better priority to the soundcard hardware interrupts, to test you have 
to reboot or - as root - do a "/sbin/service rtirq start" from a 
terminal... just in case you did not)

-- Fernando

> On Nov 12, 2011, at 9:17 PM, Fernando Lopez-Lezcano wrote:
>> On 11/12/2011 02:06 PM, John S. Dey wrote:
>>> Hi,
>>> I'm currently using 3.0.7-1.rt20.1.fc15.ccrma.x86_64.rt as my kernel
>>> on fc15 running on a thinkpad T60p with ATI graphics. I haven't been
>>> able to find settings for jackd that produce reliable real time
>>> performance. In the past I could achieve latency as presented in
>>> qjackctl of less than 10ms. Now I get xruns with latencies of 40ms
>>> and more. The stock kernel is just as good.
>> What soundcard do you have and what parameters did you use for jack?
>> (just curious).
> cat /proc/asound/cards
> 0 [Intel ]: HDA-Intel - HDA Intel
> HDA Intel at 0xee400000 irq 49
> 1 [Set ]: USB-Audio - C-Media USB Headphone Set
> C-Media USB Headphone Set at usb-0000:00:1d.0-2, full speed
> 29 [ThinkPadEC ]: ThinkPad EC - ThinkPad Console Audio Control
> ThinkPad Console Audio Control at EC reg 0x30, fw 79HT50WW-1.07
> I have varied Frames/Period and Periods/Buffer (2,3 and 4) but haven't
> been able to get
> stable results better that what is shown. I ran with both sound cards
> shown above. The rt kernel wasn't any better that the up to date stock
> kernel.
> Thanks,
> John

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