[LAU] USB period size? (WAS: tracking down xruns)

[Ng Oon-Ee]

On Tue, 2009-12-22 at 15:44 +1100, Patrick Shirkey wrote:
> 
> Are you running the usb device at 44100 or 48000? Ideally usb cards 
> should be run at 48000 with period sizes that divide perfectly into 
> 48000. i.e 100, 200, 400, etc...

Could I know more about this, please? 48000 would be the 'generally'
used (besides 96k) for USB sound cards I understand, but what's this
about period sizes? I've always thought period sizes were of the series
8, 16, 32, 64, 128, 256...