I've run across a phenomena that puzzles me. It appears that each time I start the jack server on an usb card, jack_iodelay will report a different "extra loopback latency". I've seen this phenomena on a behringer x32, and just verified it on a rme babyface. For instance with jack1 at 64/2 on the babyface, I come up with values of 232,233,234, and 266. With jack2 I saw 231, 233, 248, 318, 335. A run with jack1 at 2048/3 came up with 2589, 2590, 2633, 2634, and 2667. I also tested with jack_delay, which also comes up with different values when I restart the server. Note that on consequent invocations without restarting the server the values stay the same for the 2 utilities. Maybe not a huge problem and I suppose I'll set the latency compensation somewhere in the middle of the results, but still I'm curious of the mechanism behind this phenomena. FWIW, I don't think I've ever seen this on my pci cards, but I'll run some tests when I get to the hardware and find some extra time. -- Joakim