Comment 145 for bug 1136110

Toby: I'm sure whatever problem is caused by the hub is NOT identical to the original problem. It may have similar symptoms, but the underlying cause must be different. For example, it might be a bug in the hub itself.

Tyson: In theory, connecting a USB device through a hub should not affect any latency, DPC or other. Furthermore, in many cases there is no choice -- the design of the motherboard forces all non-high-speed devices to be routed to an on-board hub.

On the other hand, it is true that Linux's support for periodic transfers to low/full-speed USB devices is more robust in the UHCI and OHCI drivers than in the EHCI driver. This means that if your motherboard has a UHCI or OHCI controller, your DAC (or mouse!) is likely to work more reliably if plugged directly into the motherboard than if connected through a USB-2 hub. Using an old USB-1.1 hub should be about as good as going directly to the motherboard.