Pascal Bourguignon  <spam@thalassa.informatimago.com> wrote:
+---------------
| > I've heard that a modern PC running Linux can route about 1.5Gbps of
| > traffic or proxy about 1Gbps through a user-space program. I don't
| > know how accurate this is or how much it varies between "modern PCs."
...
| The bottleneck in "modern PC" is the PCI bus.
| A 32bit PCI bandwidth is no more than 133 MB/s, that's only 1064 Mb/s.
+---------------

True, if my "modern PC" you mean the cheapest desktop you can buy in
a discount store or on the web. On the other hand, most serious servers
have 66 MHz PCI-64 busses (4.2 Gb/s each) *and* multiples of those busses
and/or 133 MHz PCI-X busses (~8 Gb/s each). Midrange multiprocessor
servers (e.g., <URL:http://www.sgi.com/servers/altix/350/> might
have as many as *16* PCI-X busses, and some very large servers
(e.g., <URL:http://www.sgi.com/servers/altix/>) might have as many
as *hundreds* of PCI-X busses.

+---------------
| Most (ie. the two I tried) Gigabit Ethernet card can't handle more
| than 400 or 700 Mb/s.
+---------------

That's probably more a limitation of the I/O chipset on your "modern PC"
than the Gigabit Ethernet NICs themselves. People have certainly seen
close to "wire speed" from good-quality Gigabit Ethernet NICs on the
right platforms.


-Rob

-----
Rob Warnock			<rpw3@rpw3.org>
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