[rescue] Advice on Octanes

Kurt Huhn kurt at k-huhn.com
Tue Sep 23 19:37:04 CDT 2003

On Tue, 23 Sep 2003 16:39:47 -0700 (PDT)
Francisco Javier Mesa-Martinez wrote:

> First off, it was part of my sense of humor... not trying to offend.

None taken.  I was just surprised by your response, which seemed out of
character for you somehow.

> What I thought is that you seemed to think that the processor had a
> "dedicated" port to each component in the system, i.e. Memory and I/O.
> Which is not true, since the R10K has to do every request through the
> same pins, since IO and memory are the same as far as it is concerned.
> The only time the Xbow can be superior to a PC is when 2 processors
> are pressent in which it will allow each processor to hit either
> memory or I/O separatedly. For a single processor there is not much
> gain from the Xbow when compared to a FeeCee.

Nononono.  I know what the architecture of an Octane is like.  Yes it
has a crossbar, yes it has a heart chip, but in terms of bandwidth to
the processor, there is a two-lane highway and only so many bits can fit
on it.  However, in my experience, that bit limit is much higher on my
Octane than the P-III - even with a single R12k.

> Newer Athlon and Xeon chipsets allow for switched approaches.

I wasn't aware of this.  I find it difficult to fathom though, how is it

> And I have a completely different experience, so I am glad that you
> have the tool that you require for your job.

Related note: We have a pile of new G4 xServes in the datacenter, and a
pile of G5s on order?  Vector processing is a wonderful thing.  The
developers ran our matrix simulations on a P-IV and then forked the code
for the vector unit and ran it again, and then they threw a beer bash. 
I heard whispers of "five times faster" in intial testing from them. 
Awsome stuff.

Kurt              "You're all bastards! MTV sucks! We hates you all!"
kurt at k-huhn.com                                -- Gollum 

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