Hi, It does look like that you have two busses. Actually root hub would be a more exact term. I guess you understand this, but for general education: - Soundcards need to stream small bits of data ALL THE TIME - Hard drives burst (comparatively) HUGE chunks once in a while. This kind of operation does not mix well (=at all), when the streaming data has to received on time and with low latency. This incompatibility has nothing to do with bandwidth, it's a limitation of serial interfaces. It's not about doubling your bandwidth, it's about having two independent communication channels. After sounding like I know about this stuff, here is something I don't understand: - I have four usb controllers visible with lspci. 3 UHCI (USB1.1) and 1 EHCI (USB2) controllers. - cat /proc/interrupts shows that there are three usb-uhci modules and one ehci module, each module using a different IRQ. - With lsusb -v I see that 3 root hubs are "USB UHCI Root Hub" and one is "Intel Corp. 82801DB USB2". This looks like all USB2 devices are connected to this hub. That means that there is a strong possibility that at least in my systems, all USB2 devices would share the same hub, regardless of which usb jack the device is plugged into. I do not know how this works out in the driver level, but it looks quite suspicious. Does anyone have better knowledge about this? Could you enlighten us? Sampo On Thu, 2004-06-10 at 22:00, Frank Barknecht wrote: > Is there a way to find out how many buses there with things like > lsusb? Or being concrete again: Does this output mean, that I have two > busses, that should be able to provide the double bandwidth? > > $ /usr/sbin/lsusb > Bus 002 Device 001: ID 0000:0000 > Bus 001 Device 002: ID 0547:1002 Anchor Chips, Inc. > Bus 001 Device 001: ID 0000:0000 > > This would be interesting as I might consider using some data > intensive devices on one bus while the other is taken by the > soundcard. > > Ciao
