Re: FYI: I2O Architecture (fwd)

Alan Cox (
Wed, 20 Nov 1996 19:30:58 +0000 (GMT)

> Despite the pros-and-cons, most of the OS vendors seem to be behind this
> (Microsoft, Novell, SCO, Digitial...), and the 'standard' is
> currently closed to outsiders.

Makes sense. Otherwise outsiders go and run stuff faster than them. Also
be aware big vendors buy into anything cheap and potential useful

> With the processing power that will be on some of the I2O cards, we
> might find network protocol stacks (TCP?), etc, being off-loaded from the
> central CPUs.
> Would this be a step backwards or forwards from SMP?

It depends is the answer. It can be a step backwards from single processors
even. Its costlier it adds latency and it may actually slow things down.
Contrary to some perceptions things like networking and disk I/O are not
CPU intensive per se. What costs is stuff like VM strategy - which is hard
to hive off, and in the networking case its just the fact you get hit at

Now you can either hand the network packets to someone else or handle them
locally. If you handle them locally then you've got to handle them. Your
network card can do checksums (eg sun hme cards), but the data still has
to go to user space and through your web server. If its going somewhere
else you don't need I2O, you need an existing device popularly called
a "router".