I'm going against the grain here.. I haven't mixed any higher than 256. I wasn't aware that plugins work better at higher period values, although I only use Linux and am not sure if that is true for the LinuxDSP or Harrison plugins.. I only relax my latency settings as xruns (glitches)start appearing.
In recording I always start at 64. I'm running a fairly optimised Gentoo system with an Intel 3770k running at 4.5 Ghz and up until now have been using a Focusrite Saffire 10io converter.. However I have just picked up an Allen & Heath Zed R16, so that could potentially change (although initial testing shows recording at 64 periods should be fine).
I would also assume that once Harrison 3 comes out the situation should improve for everybody (based on Ardour 3's ability to run DSP across multiple cores, whereas Harrison based on Ardour 2, has one thread for all audio, including DSP and a separate thread for MIDI control and one for UI).
In recording I always start at 64. I'm running a fairly optimised Gentoo system with an Intel 3770k running at 4.5 Ghz and up until now have been using a Focusrite Saffire 10io converter.. However I have just picked up an Allen & Heath Zed R16, so that could potentially change (although initial testing shows recording at 64 periods should be fine).
I would also assume that once Harrison 3 comes out the situation should improve for everybody (based on Ardour 3's ability to run DSP across multiple cores, whereas Harrison based on Ardour 2, has one thread for all audio, including DSP and a separate thread for MIDI control and one for UI).