I am running Ubuntu Studio 12.04 x64, 3.2.0-23-lowlatency on a Dell i3 M350 (2.27GHz) laptop with 4GB RAM. I typically run with networking disabled.
I recently bought a Focusrite Scarlett 2i2 to use with Ardour mainly, for some very light multi-tracking. Through trial and error I eventually managed to find JACK settings that allowed me to record without xruns; Frames:1024, Periods:3, Sample Rate: 44100. If I reduce either the frames or periods I do get xruns.
The estimated latency according to qjackctl is 64msec. This number goes down if I *increase* the sample rate - something I found counter-intuitive at first (although I later found that the latency is calculated as 'Frames * Periods / Sample Rate') - however increasing the sample rate also causes xruns to appear.
I'd like to try and achieve a lower latency when monitoring through software, as I believe the hardware I'm running is capable of something better, and am finding a noticeable delay when multi-tracking (the audio device does support hardware monitoring, however I find this a bit too quiet, even when the headphone knob is cranked).
I've attached a screenshot (qjackctl.png) - am I missing anything? It's worth pointing out that Ardour reports a slightly lower latency than qjackctl, however it still feels unusable in its current state.
Any advice gratefully received.