Hi all, just got this DM from Greg:
I was wondering if you new how well the latency compensation worked via jack when adding tracks or punching in? It would be great if you could write up a post about that on the forum
On closer inspection Jack doesn't add any latency at all, only additional CPU overhead: http://jackaudio.org/no_extra_latency
I've just recorded and mixed a large session with Jack sitting between the Madi FX and Pro Tools, and had absolutely no issues whatsoever. My Mac isn't particularly modern either, so the CPU overhead doesn't appear to be dramatic.
It's worth noting that the CPU usage for Jack goes up with the number of channels used, so if, for example, you're tracking with up to 32 channels of input but only using 2 or 4 outputs until mix time, you can save some CPU during tracking by reducing the number of virtual output channels.
I didn't find this necessary, but I imagine some people might.
I do find this all a bit disappointing though to be honest. Yes, it's a limitation in Pro Tools Native, but also I expect more from RME than to release a product like this with evidently no testing on a very widely used DAW. We're not talking about corner-case instability here, we're talking about complete failure to load Pro Tools, so either it simply wasn't tested or RME decided it didn't matter. It does appear other vendors such as UA and SSL deal with the issue more elegantly.
This aside, now my Madi FX is up and running, I am hugely impressed with it on all other fronts.