Good PCI-X Chipsets -- exist?

[Eric Roman]

Do you have any idea which PCI-X chipsets are the fastest?

I'm trying to decide between the two new SuperMicro boards (SWGC vs.  E7501).
I can't find any benchmarks that accurately describe the top performance of
their PCI-X buses.

We're planning to do some InfiniBand (4X) testing (possibly Myrinet as well)
on these boxes, so we're quite interested in making sure that the PCI-X is
as fast as possible.  We're hoping (dreaming?) of saturating the IB with
MPI traffic.  I've seen rumors of 800MB/s w/ SWGC.  Is E7501 any faster?
E7500?  Others?

Anyway, if you have good (i.e. measured, with anything relevant) numbers
for these boards (either is good, both is better), I'd love to hear about
it.

Thanks!

 - E

-- 
Eric Roman                       Computational Research Division
510-486-6420                     Berkeley Lab