On Tuesday 20 September 2005 14:25, Mark Knecht wrote: > On 9/20/05, Duncan <[EMAIL PROTECTED]> wrote: > > I'm not familiar with the term "xrun", so this may be entirely off the > > wall, but have you confirmed the hard drive is running DMA? If your > > chipset or SATA drivers are wrong, and your hard drive is having to run > > in legacy interrupt mode instead of DMA mode, it *WILL* destroy latency > > and generally make the system unusable for any sort of real-time work at > > all, regardless of the other kernel patches applied. So... in addition > > to checking the network drivers, investigate the hard drive and chipset > > I/O drivers as well, and confirm you ARE running DMA mode. > > Thanks, yes, DMA is running, as far as I can tell. hdparm -tT returns > numbers that are >50MB/S. > > xruns are a term specific to the Jack server > (jack-audio-connection-kit) that tell us whether we've had and overrun > or an underrun. It's would be off topic to go deeply into how Jack > operates when talking to sound cards, but take it to mean something > bad has happened with real-time audio data.
Nah, it's more alsa specific. What soundcard do you use? Some soundcards are more crappy than others (especially onboard ones). I guess it should support DMA as even the soundblaster pro did so. Soundcards do however provide various levels of hardware accelleration. > Interestingly Jack runs from memory so hard drive performance should > not cause major problems unless it's not interruptable in a more or > less real-time way. On my Gentoo 32-bit machines (using Via and ATI > chipsets) I've not had to install any real-time patches and can still > run reliable at sub-2mS latencies. On those machines I can do pretty > much anything, browse the web with firefox, do and emerge sync, etc., > and I get no xruns. On this AMD64/NForce4 machine and emerge sync > causes xruns immediately, indicating the sound card is getting starved > for data. Good chance the soundcard buffer is smaller or the driver is crappy. You could try to take the soundcard from the old machine and put it in the new one. Paul -- Paul de Vrieze Gentoo Developer Mail: [EMAIL PROTECTED] Homepage: http://www.devrieze.net
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