In Live 8.2.2 (and going back as long as I can remember with Live 8 ), starting a new set, latency will be very low/nonexistent. After adding devices, plugins, etc latency starts to creep up. Latency increases are particularly noticeable after "pauses" caused by a CPU-heavy plugin, such as Trilian, upon insert, opening its GUI, or changing patches. Happens with any plugin but especially bad with large ones. Naturally, if audio is playing when I do this, there is a gap.
But the latency doesn't go down. It just stays high until I disable the audio engine and then re-enable it. If I do this, magically latency is back down to a tolerable level. Now, depending on the set, it may never get down to where it was when I started; this is expected after there is a lot going on in the set. However, I still have to cycle the audio engine even to get down to this baseline latency. The result is a clumsy workflow whereby, whenever I want to play in a new figure, I need to cycle the audio engine.
This is, of course, in sets where there are no linear-phase or other intrinsically latent plugins going.
To be clear, what I mean by "latency" is the time between when I press a note on my keyboard and when audio is heard. I am not doing any audio recording. The inputs on my Duet are not enabled.
I did some experimenting with Live 7.0.18 and the latency, while existent, is not nearly as bad, even after working with large plugins.
So, what seems to be missing is the software recognizing the fact that latency just went up. It should flip the latency back to where it was automatically.
gear:
MacBook Pro 2.53 GHz
8 GB RAM
Mac OS 10.6.3
Live 8.2.2
Apogee Duet
Axiom 49 II
APC40
G-Tech External HDD