Quanta Building MIT's $100 Laptops (eWeek)

Posted Dec 20, 2005 8:58 UTC (Tue) by Duncan (guest, #6647) [Link]

USB was defined by Intel, back when x86 CPUs were first going over about
500 MHz and they were searching for ways to use more CPU, so they could
continue to sell faster chips, given that 500 MHz was really the level at
which the CPU was "fast enough" (on x86) for what most folks did with it,
for the first time in history.

Thus, USB is a CPU intensive hosted protocol, requiring a CPU at the
"host" end, altho it requires far less at the "gadget" end. Compare it to
the "Fire Wire" of the time, a similar usage protocol, similar cables, but
MUCH faster, and using a peer2peer protocol rather than the hosted
protocol of USB. The p2p interface required a more expensive interface
chip in each item, but as it was p2p rather than hosted, it didn't use as
much CPU and all ends were the same. The additional incremental expense
for each gadget, in addition to the fact that Apple tried to keep the Fire
Wire name proprietary at first, and the difference between Apple and
Intel, was the reason USB became popular much faster than Fire Wire.
(Apple eventually relented and yielded the Fire Wire name to the industry
group defining and controlling the standard, but it was really too late by
then, and the incremental cost add of the interface for gadget makers did
nothing to help.)

Duncan