> > Another thing about the quattro is that even the windows drivers will > not allow you to record and playback on all 4 channels at one time. > > You can use > > 4 in, 2 out 48khz 24 bit > 2 in, 4 out > 2 in, 2 out 94 khz 24 bit > > I think I am running up against this with my latest attempts. It may be > that the quattro cannot do all 8 channels because of a hardware switch > maybe for power consumption or something. They do run awfully hot and I > can imagine that it would be possible to melt something if their is too > much power running through them. > USB 1.0/1.1 is built on a 12Mb/Sec physical layer. 96000 * 24-bits * 4-channels = 9.216Mb/S if I did the calculations correctly. I think that's probably more than USB can really handle. When I worked for a company that did USB hardware, we found in many PCs (at that time - 1996-1999) that most USB implementations would really do much more than about 2Mb/Sec reliably. The newer implementations are much better, but these numbers bring you up to 75% bus efficiency. Even 1394 doesn't get much beyond that and it uses much larger packet sizes to get some of that.
