Sure, on a Mac you can actually see, in Audio-MIDI Setup, 40 in and 40 out, maybe even 52 in and 52 out. But Pro Tools 9 has an actual firewire limit on playback channels. I discussed this with the Lynx Aurora techs, and they have just now come up with a driver that will allow 32 discrete playback channels with Pro Tools and two Lynx Aurora 16 interfaces. I tried for many hours to get more than 26 channels out of my Firestudio Projects, 4 daisy-chained together, with no luck. It would work with Presonus' Studio One software, but not with Pro Tools. I finally got this all to work with two Lynx AES 16e cards in my Mac Desktop Pro and using two Lynx Aurora 16s, with their new beta driver - even they were having problems getting 32 physical
channels of playback from Pro Tools 9!