hah, Google served up a very necro thread from 2005...
I thought this sounded pretty cool in a PT12 description I ran across:
"
Low Latency Recording BufferAnother huge deal for PT users is the addition of a second audio buffer. The new Avid Audio Engine automatically manages playback buffer sizes during normal playback. The second you put an audio or instrument track into record or input the second buffer, which you set in the Playback Engine window, comes into play.
Your input signal buffer can be at 64 samples, while the rest of the mix, complete with posh limiters etc, can be using a buffer as big as 2048 samples. This means you can overdub into a session with up to 16,000 samples latency, and monitor your input through plug-ins with little or none."
Is there something like this in Sonar already?