If Hi-Speed USB 2.0 is 40X faster, why is it that a CD-R/W, for example, is only 6X faster?
The 40X speed improvement is specific to the bus. What this literally means, is that the bus is no longer the bottleneck in performance. The actual performance improvement for a given product is dependent on how fast that product can run. Over time, you should see product vendors improving their products to take advantage of the 40X bus.
