On 4/20/07, Vince Wiggins, StataCorp <[email protected]> wrote:
It is hard to say, other than recognizing that many quad-core processors are
newer than their dual-core brethren and therefore may be faster and have
larger caches.
Well it looks like the quad (Intel) processors that I am looking at
are running at around 2GHz clock, and have 2x4Mb L2 cache, while the
dual cores have clocks up into 3GHz with a single 4Mb cache. Of course
the 2-quad-processor machine is much more for the many than the
2-dual-core processor machine, in the end, and I can get either under
my budget... but then also Stata/8P is pricier than Stata/4P.
Processor architectures differ in many ways and these ways are not limited to
the difference between dual- and quad-core versions. Even so, we have not
found many consistent performance difference among processor architectures or
the multi-core vs. multi-processor computers. We see differences, they just
do not generalize across all commands or even across problem sizes.
Well the command I would care a lot about generalizability of the
speed is -gllamm-, and rumors are that a lot of MP-ing stuff is
related to it. Is that true?
For a given number of cores or processors, our recommendation is that first
you get the fastest processors you can and that second you get processors with
the largest available on-board cache memory.
That's what I was going to do, anyway :))
On 4/20/07, Austin Nichols <[email protected]> wrote:
Stas--
You may be interested in this thread:
http://www.dailytech.com/Aggressive+Intel+Quadcore+Price+Cuts+Before+Barcelona/article6488.htm
that says Intel's Q6600 (2.40 GHz, 8MB cache, 1066 MHz FSB) will be
$266 later this year (it's currently about $1000 for just the
processor).
Note one exchange way down the page between "cheetah2K" who claims
"US$266 is good for a 2 x Dual core. Intel's Quads aren't real quads"
and "Flunk" who replies "The fact that it's two dies on one chip is
rather immateral if it doesn't [affect] performance (since we don't
have any real-world figures it would be silly to argue this point). "
Will you let me know if you find anything out offline? I'm interested
in getting a Quad-core machine later this year, and upgrading to
Stata/MP of course.
Well I have the time constraints when I should spend my University
kilobucks on this :)). So I'll just get the best one I can for the
money when it is time. As for the performance, Stata Corp. has the
report... and if they were especially kind, they would have the
reproducible do-files to accompany it... which I am pretty sure are
available upon request... which I won't bother doing now as I don't
really have MP systems to run it on.
--
Stas Kolenikov
http://stas.kolenikov.name
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