[PlanetCCRMA] A general Jack question - which

Fernando Pablo Lopez-Lezcano nando@ccrma.Stanford.EDU
Fri Jan 16 10:48:01 2004


> Two more questions I have been wondering:
> 
> -My hardware does 16-bit and 44.1 KHz. Can I run Jack and record in Ardour at 
> 96 Khz if my hardware is powerful enough for that? 

The sampling rate is only limited by what the ALSA drivers can do. If
you have a card that can do 96KHz and that is supported by ALSA then you
should be fine. 

> -Latency: When I run Jack with 16/44.1 and 1024 frames the HW latency is 46.4 ms. 
> Jack gives me the following output: 
> load = 0.1941 max usecs: 46.000, spare = 23173.000. 
> Does the usecs: refer to latency? Am I correct concluding that the latency caused
> by Jack / other software components is max 46 usecs at that point and hence the 
> total latency is below 50 ms?

That is (I think) the number of microsecond used by jack and all jack
clients, and "spare" is what time is left in the cycle. It does not have
to do with latency. If "spare" gets close to 0 then you don't have
enough processor power to do what you want to do and stay running in
realtime. 

-- Fernando