2/4     How come USB 2.0's speed on spec is faster than IEEE 1394 but I
        can never make it come even close?
        \_ You can't confuse peak throughput rates with actual sustained
           rates. The USB and FireWire protocols are vastly different.
           Take AGP 2x, 4x, and 8x for example. One would think that
           each is twice as fast as the one before. But with the way
           AGP is speced, all requests must round up to the nearest
           common clock (running at 15ns). So in 8x, 32-bytes can be
           transfered in 1 reference clock cycle but if the GPU makes
           a 16-byte request, half the bandwidth is thrown away. Also,
           because AGP is a shared bus, turn-around cycles will cause
           performance degradation when the bus alternates direction.
           My guess is that USB is more vulnerable to these kinds of
           things than 1394 is.
        \_ What are you benchmarking with, senor
        \_ There's two separate speed for USB 2.0: one at only 10s of MBB/s
           and another at the full speed off 100s.  And then there're
           those manufacturers that label USB 1.1 devices as USB2.
           \_ I hate that.  The bastards put a 2.0 cable on a 1.1 device and
              *lie* calling it a 2.0 device.
              \- why dont you get john edwards to represent you in a CLASS
                 ACTION suit ... along the lines of the Great Monitor Dimension
                 suit. --psb
                 \_ uhm... yeah... sure... ooookkkkk... you feeling alright?
              \_ USB 2.0 Hi-Speed (fast), USB 2.0 Full-Speed (slow)
                 Since when is marketing a crime?
                 \_ Yes, there are those two sets of speed in the spec for
                    USB 2.0.  But aside from that, what we're complaining here
                    is about the manufacturers that are marketing USB 1.1
                    devices as USB2.
                    \_ You've been whooshed.  See:
             http://www.dilbert.com/comics/dilbert/archive/dilbert-20040204.html
                    \_ USB 2.0 Full-Speed == USB 1.1
        \_ USB has a lot of overhead.  Plus, when dealing with USB 2 devices,
           you need to look for the "hi-speed" label (not "full-speed")
        \_ USB is designed to be cheap and has very simple wiring.  Firewire
           has better electrical characteristics, but costs more to implement
           and to wire up.  (There are more wires, too, as each signal cable
           has a separate ground.)  Basically, USB==cheap, IEEE1394==reliable.
           \_ If you're talking about cost, remember each 1394 port subsidizes
              Apple.  USB is an open standard.