[vortex] two NICs in a riser card?

[Martin Siegert]

Thanks Donald, this has helped a lot!

On Sat, Jul 14, 2001 at 09:40:21AM -0400, Donald Becker wrote:
> On Fri, 13 Jul 2001, Martin Siegert wrote:
> 
> > this may be a stupid question:
> > 
> > is it possible to have two NICs in a riser card?
> 
> Only if the riser card plugs into a slot specifically designed to be
> "magic" for that riser card, and the riser has active components.

We now found a different riser card that has such "active components".
I do not know whether the PCI slot 2 on the Tyan Thunder K7 has any specific
magic, but I now see two 3c905c NICs (besides the two onboard 3c980).

> > I have two 3c905cx-txm cards plugged into a riser card, which in turn
> > plugs into a single PCI slot on the motherboard.
> 
> A generic motherboard?  No, it won't work.
> 
> > When the box boots only one of the two cards is recogniced.
> 
> I would expect that behavior.  If you solve the PCI config space issue,
> you are still sharing bus master lines.

>From what I get from netperf now indicates that this new riser card
actually does the trick: I am getting 280 Mbit/s over 3 channel-bonded
NICs (which include both NICs on the riser) and 94 Mbit/s over the
remaining NIC (while running both netperf benchmarks at the same time).
> 
> > Can this be done or do I have to purchase a dual port NIC?
> 
> A dual-port NIC will have the proper design: only one chip connected to
> the PCI bus.  That chip will be PCI bus bridge.

Not having to buy a dual-port NIC will save a ton of money :-)

Regards,
Martin

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Martin Siegert
Academic Computing Services                        phone: (604) 291-4691
Simon Fraser University                            fax:   (604) 291-4242
Burnaby, British Columbia                          email: siegert@sfu.ca
Canada  V5A 1S6
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