[SunRescue] Re: New Netra

[James Lockwood]

On Wed, 17 Jan 2001, Reagen Ward wrote:

> My main point is that I see Beowulf mentioned a LOT, even see folks talking
> about building Beowulf clusters out of piles of old 486 machines (and they're
> not joking sometimes!), but the applications are rather limited due to the
> design / requirements of an MPI system.

Right.

COWs (Clusters Of Workstations, as they used to commonly be known) are
exceptionally cost-effective at solving a certain class of problems.  If
your problem is trivially parallelizable then they're wonderful, otherwise
the interconnect latency will kill you.  Large NUMA systems (such as those
from SGI) attempt to straddle the line and they do so effectively IMHO.

It's odd that the term "Beowulf" has received so much press, it really
offers very little over other MPI/PVM setups.  A shared PID space is kind
of nifty but offers nothing which can't be achieved in other ways, and
interface bonding is something which belongs in the OS itself (and can be 
faked in most cases with multiple routes to each system and an IP alias
bound to loopback).

-James