On Tuesday 23 May 2006 15:27, Joachim Worringen wrote: > Eugen Leitl wrote: > > Switches (crossbars) don't scale for very many ports. Especially if you > > have to do cut-through switching at those high speeds. It would be good > > if each NIC would came with an integrated switch, with enough ports to > > wire at least a 3d torus (where you route/switch messages via Bresenham). > > You know that such NICS do exist for some years? If not, take a look at the > SCI interfaces at http://www.dolphinics.com. Only a few ns per NIC routing > latency. However, all HPC switch vendors will tell you that their switches > scale great, and have full bisection bandwidth. And I guess they are not > totally wrong. > > > In regards to keeping the wires short, does this IBM trick of keeping all > > wires equal-length work well on 3d lattices, and above? This would seem > > to be a must for those coming (hopefully) Hypertransport motherboards > > with connectors. > > I assume you refer to the "interleaving" of node connections? Is this an > IBM patent? It *might* be after all the patents I've seen so far... > > The cabling is already quite tricky for 3D setups. I don't think you would > like to go beyond. There are good reasons why nobody has done it yet.
We have a 5x8x5 SCI 3d torus, it is _NOT_ fun to cable or debug. I much prefer my IB switches. /Peter > Joachim -- ------------------------------------------------------------ Peter Kjellstrom | E-mail: [EMAIL PROTECTED] National Supercomputer Centre | Sweden | http://www.nsc.liu.se
pgpGKHWCFOEXO.pgp
Description: PGP signature
_______________________________________________ Beowulf mailing list, [email protected] To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
