Re: Broadcast vs. point-to-point

Eugene Leitl (
Thu, 26 Nov 1998 19:53:19 +0100

Dan Clemmensen writes:

> Again, look at the usable bandwidth per node for the given solutions.
> It's below 100Kbps. Radio is wonderful, but I want 100Mbps per node,
> and I want a high node density.

A full-duplex FastEthernet link gives you roughly twice that/port. Using multiple NICs/node gives you even more bandwidth, and one which scales up linearly with node size (ditto disk bandwidth, if each node is equipped with individual disk(s)). Multiple-port NICs, even with switching functionality, are not unprecendented. In fact, I'll build my 8-node Beowulf(cub) switchless, with at least 3 NICs/node early next year. Much unexploited potential lies hidden in U-Net and 3D Now! SIMD instructions as well. Of course you can start instantly with MPI/PVM and PVFS, and use the cluster as a vanilla parallel supercomputer, using the advanced features peu a peu.