Recommended PCI gigabit ethernet card? OT: PC Gigabit Throughput Question

Drew Van Zandt drew.vanzandt at gmail.com
Fri Jun 15 22:15:14 EDT 2007


There are still collisions (of a sort) even on full-duplex switched
networks.  Two 10 Mbit devices can't talk full speed to the same 10
Mbit conversation partner, obviously.  Store-and-forward switches and
routers help with short-term congestion, but even without 2-to-1
bottlenecks, most switches can't maintain wirespeed on all ports
simultaneously.  Wirespeed routing with a Linux box isn't practical
with real high-speed stuff, even dedicated hardware has trouble
keeping up.  (Even a big box would have trouble with more than 5 or 6
GbE cards, let alone 10 GbE.)

10 GbE actually has something along the lines of "padding" bits here
and there in the middle of packets, not just between frames, so that
they can be dropped (or added to, I think?) if the clocks on the two
ends of the link aren't quite close enough - it's been a while since I
worked on that hardware, so I don't remember very well.  In any case,
tuning your Ethernet is a valuable exercise for latency reasons, not
just bandwidth reasons...both matter.

I miss network hardware.  :-)

--DTVZ


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