Subject: Re: ohci and isochronous transfers
To: Thomas Runge <>
From: Todd Vierling <>
List: netbsd-users
Date: 11/28/2004 17:11:26
On Sun, 28 Nov 2004, Thomas Runge wrote:

> But whenever I connect two cameras to the same root hub:
> I get lots of errors while trying to capture data:
> ohci1: 249 scheduling overruns

> Now I got curious and tried that on XP using amcap.exe. It worked
> either way, but the second stream was way slower when both cameras
> where using the same hub.[...] So, it can't be a hardware limit/problem.

This is a contradiction.  The fact that the second stream was slower under
XP was a crystal clear indicator of a hardware limitation.  XP just doesn't
have a console log to tell you about the flat-topping of your USB1 bandwidth
(since the devices are apparently not USB2).

-- Todd Vierling <> <>