[rescue] Advice on Octanes
Francisco Javier Mesa-Martinez
lefa at ucsc.edu
Wed Sep 24 00:50:17 CDT 2003
On Wed, 24 Sep 2003, Dave McGuire wrote:
> I do have a great deal of respect for your knowledge, but please keep
> in mind the fact that getting a PhD proves that you can please a
> professor...not that you know what you're talking about.
Huh? Obviously you have never attempted to obtain a PhD in science have
you? :) If that floats your boat.....
> Now, I believe that YOU *DO* know what you're talking about...despite
> the PhD thing.
> In this case, however, having put them side by side, I've seen very
> different results. As have several others here. PhD or not, "them's
> the facts".
> > Shees, I am sure you could tell the Stream guys something that only you
> > know:
> > SGI Octane2/R12k-400 : 514.1 MBps
> > Pentium III/733-CM(pgi) : 685.7 MBps
> > OK?
> > So last time I checked, 514.1 < 685.7 Or maybe math is biased too? :)
> That's nice. Why is the Octane faster, then?
Huh? Dave hello? Hello there, in triad part of stream the P3/733 hardly
the latest and greates gets over 160MBps advantage over an octane
R12K/400 (a pretty nice configuration). Let me work the math for you, the
P3 is 33% faster when it comes to memory throughput. Now I don't know if
you are just blinded by the zeal but you have to understand from those
numbers why SGI and co are in the whole they are in right now.
The Octane has a great OS going for it, the problem is that whether your
like it or not, Intel with their brute force approach can make their pins
go awefully fast.
The other thing that many people neglect is that actually the P3 and Co
have a slight advantage in their CISCness, which makes them utilize memory
bandwidth better. Giving the same BW to memory, a CISC machine is bound to
utilize it better because it requires a smaller instruction bandwidth
compared to a RISC machine. And lastly the cache in a P3 is right in the
core, whereas the R10/12K has to go off chip for the L2, again that makes
a huuuuughe difference. If now you go and look at the recent Athlon
offerings with a 9-wide issue capability running at 3Ghz, well... I may
not like the architecture but hte raw power that AMD and Intel are fitting
in their silicon at the pricepoints they are offering....
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