On Wed, 26 May 2010, B.Vinai Kumar wrote: > To test this, I did the following experiment. > > Under the same ehci controller, I connected the > following devices. > > 1) USB 2.0 Mass Storage and > 2) USB 2.0 Web Cam. > > Using hard disk utility tool I tried to measure the usb bandwidth > of the mass storage device with and with out camera. > > The read values shown by the tool are: > 1) With USB 2.0 Camera: Avg Speed - 13.1 MB/sec > 2) With out USB 2.0 Camera: Avg Speed - 13.3 MB/sec > > There is not much difference between them. That's not much of a test. Keep in mind that the actual capacity of your USB 2.0 bus is about 60 MB/s. You would need to attach at least 4 of those mass storage devices and use them all simultaneously to be sure of seeing any effects. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
