On 9/20/05, Paul de Vrieze <[EMAIL PROTECTED]> wrote: > 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.
That's not the problem here. The card is an RME HDSP 9652. It ran in my older Asus/Via/Athlon-XP/Gentoo-32-bit machine just fine. I've built the new Asus/NForce4/Athlon64/Gentoo-64-bit machine and transfered the same card of here so I know the card and drivers are fine, at least in a 32-bit environment. > > > 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. As you can see, that's what I did! :-) - Mark -- [email protected] mailing list
