🚀 go-pugleaf

simonich@croatia.eng.hou.compaq.com (Chris Simonich) writes:

Dear Compaq'ers: please look at SCI again.

> We have received this response from several people.  We 
> disagree.  For one SCI had a physical topology (a ring) that 
> is not suitable for expansion I/O.  Yes, we know you can run 
> the ring to and from the same board and create a topology 

A ring is not the only topology for SCI.  A ring is *convenient* 
for several applications, however any topology that can
be devised from point-to-point links works.

> around here) were trying to solve different problems with 
> cost, not bandwidth, being the major one.  The fact that the 
> 'C' in SCI stands for coherent I think brings out one of the 
> differences in approach.  We needed an I/O interface and 

It's true that 33% of the name is "COHERENT", but in reality,
the overhead is not a whole lot (coherence adds 2 bits in the packet
header) and you can quite easily skip the coherence aspects of the
protocol if you want to, *while leaving yourself the option to add
it in future parts*.

-- 
Rajeev Jog
------------------------------------------------------------------------------
Kubota Pacific Computer Inc.                                   +1 408 727 8100
2630 Walsh Avenue, Santa Clara, CA. 95051-0905, USA.               jog@kpc.com