[LAU] Latency and USB interfaces

[Tim Goetze]

[Robin Gareus]
>On 01/08/2014 05:54 PM, James Stone wrote:
>> Also, how meaningful is the reported jackd buffer size in terms of
>> actual latency? 
>
>jack buffer size is only meaningful within jack.

I was under the impression that in an optimal setup (jackd -d alsa -d
hw:$X), the jack buffer/period setup is identical to what the driver
uses to communicate with the hardware.  

In fact, examining the ALSA driver parameters[*] while jackd is
running confirms this for both the UCG-102 USB and the ice1712-based
PCI interface here.

Tim

[*] /proc/asound/card$X/pcm0[cp]/sub0/[hs]w_params