LinuxMusicians

Presonus will tell you functionally is sketchy at best on 3.0 USB regardless of platform.

I'm suggesting that Ubuntu Studio is not recognizeing USB 2.0 ports correctly.

I gave up and used another computer and everything works fine. My theory was that while my Dell laptop had 5 USB ports (both 2.0 and 3.0) Ubuntu Studio 16. 04 was treating them all as 3.0

I would love to see this answered.

Copeau wrote: I've got a clue, but I don't know how to deal with it : as soon as I start JACK (using the audiobox), the root process called "irq/40-xhci_hcd" starts using a lot of CPU..?

Copeau, How do you see what root process are running when you start jack?

Ubunto studio 14.04, Ardour 4.6 -My presonus 1818VSL works great as far as being "seen" and recognized as 18 inputs and 18 out. I haven't tried recording as I can't get the playback right. I noticed a problem when trying to playback a previous Ardour session (drum loop only) Playback had s...