[X4U] FireWire vs. USB 2.0

[Randy B.Singer]

Hector Luna said:

>I don't know about purposely crippling, but I do know that USB was
>created as replacement bus for PS/2 devices. It was meant for
>keyboards and mice. I know that if you put a USB 1.2 device on a USB 2
>bus, the speed drops down to USB 1.2 and I know that when given an
>choice between USB and IEEE 1394, I will go w/ FireWire every single
>time...

There is quite a bit of misinformation going around about USB 2.0.

A USB 1.1  device on a USB 2.0 bus can only ever run at USB 1.1 speeds.

However, if you connect a USB 1.1 device to a USB 2.0 hub connected to a 
USB 2.0 port, and other USB 2.0 devices are connected to that USB 2.0 
hub, the USB 2.0 devices will run at normal USB 2.0 speeds (less some 
overhead).  Of course the USB 1.1 device will still only run at USB 1.1 
speeds.

Things don't slow down on a USB 2.0 bus just because you add a USB 1.1 
device to the chain.  They only slow down if you use a USB 1.1 hub 
somewhere in the chain, and then only for the things attached downstream 
of the USB 1.1 hub.





Randy B. Singer
Co-Author of: The Macintosh Bible (4th, 5th and 6th editions)

Routine OS X Maintenance and Generic Troubleshooting
http://www.macattorney.com/ts.html