10gigE link with FreeBSD hosts ?

[George Sanders]

>Can't get 10 gigabit thru a PCI-X slot, it doesnt have the bandwidth, you need PCI Express, in 
>fact you will find that lots of factors will come into play and might keep you from achieving
>optimal thruput.
>
>>For a two port adapter you will need an 8x PCIE slot, preferably Gen 2, and if all three systems
>don't have that its gonna slow everyone down.
>
>Further, once you involve packet forwarding it gets even more demanding. 
>
>Trying to do it 'on the cheap' and you might get 3 or 4 Gb, maybe even worse depending.



Thanks.  I just spoke of pci-x because that was the form factor of the Sun adapter.

Ok, so let's say I have pci-e 16 or 8x for all adapters, again with the same "just out of date"
commodity pcs (intel core or c2d, etc.) and the same network layout:

(a) <-- cable --> (b) <-- cable --> (c)

you're saying I can start to approach actual 10 gb/s throughput ?

I guess there is one layer of packet forwarding in place, since I am bridging on (b) ... but is that going to just be a small (10% ?)
hit, or are we talking 50% ?

Finally, are a few (5 or 6) simple ipfw rules (like, block tcp 130, or block xmas tree packets, etc.) going to kill me ?

Thanks.