[LAU] a NEW question about pitch and speed

Steve Fosdick sjflists at btinternet.com
Wed Jun 2 09:05:19 UTC 2010


On Mon, 31 May 2010 15:08:09 -0700
Niels Mayer <nielsmayer at gmail.com> wrote:

> Just a random thought:
> 
> in ALSAmixer, if they exist, check the values of  'Multi Track Rate
> Locking' and 'Multi Track Rate Reset' .
> 
> Both should be off. 'M' for mute will turn them off and on. These
> settings seem "sticky" so you'll need to  unload/reload the drivers,
> or reboot, in order for then to take effect. [[ if any alsa expert has
> opinions on what these settings are for -- other than causing massive,
>  inexplicable hard-to-debug problems with soundcards and/or causing
> Jackd to lockup when they're set... ]]
> 
> Much more rarely, I've also seen problems w/ "ondemand" scheduling
> (CPU clock changes) versus "performance" (steady clock at top speed).
> for example, on a dual processor machine, as root, try:
> /usr/bin/cpufreq-selector -c 0 -g performance ;
> /usr/bin/cpufreq-selector -c 1 -g performance
> For example, if you use the program 'mixxx' and output to ALSA
> directly, running in "ondemand" mode causes it to lock up. Running it
> through jack allows it to work in either ondemand or performance mode.

Is this anything to do with one of the multi-core processors, sorry I
forget which one, where changing processor clock rate for power saving
reasons could cause the TSC registers on each core to drift appart?

Steve.


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