🚀 go-pugleaf

In article <7ilr3u$r6s$1@sparcserver.lrz-muenchen.de>,
  kuhn@lpr.e-technik.tu-muenchen.de.nospam wrote:
> In comp.os.linux.hardware Totally Lost <idletime@my-deja.com> wrote:
>
> : Ok, we'll use your numbers... $1000 system, with an additional $150
> : that is 15% more, not 50% more, for that you get a 10-20% speed up,
> : a very small part of the time (doesn't speed up editing, backups,
> : installs, web browsing, or most other single command activities that
> : we occupy our time with in front of the computer). It does however
> : speed up a few tasks that some people do frequently.
>
> My Calculation:
>
>                      Price   SpeedUp
> 2xCeleron333    PC   $1150    60-80%
> 2xPentiumII/350 PC   $1700    70-90%

Ok Before you asserted $150 difference, now you've raised that to to
$550 ... The 30% difference in your vs my CPU costs at $150 wasn't
worth the diversion, but the reality is that for someone building
a system the difference is about $100 on a dual system:

http://www.shopper.com/pfind/cpu.pentii.333mmx.html	$125.50
http://www.shopper.com/pfind/cpu.cel.333mmx.128k.html	$ 72.95
CPU Price difference: Uni $52.55, Dual $105.10

So, a 9% increase in cost for a Dual PII, delivers a 20% speed up
by your benchmarks. The same 9% also makes the system stable for
working sets that are 5-8 times larger. Stated in reverse, saving
the 9% in system cost, reduced the performance by 20% for your
benchmarks ... that is NOT a good value from a price/performance
perspective ... expecially when the price/performance tradeoff gets much
much worse for applications with larger working sets with Celerons.

How is it that Dual Celerons are better? Simply that they may be
overclocked higher, which for small working set computational
applications makes them a bit faster. However, if the working set
includes the normal X11, filesystem and/or networking OS features, the
working set is then expected to be significantly larger than 128K,
and there is a significant risk the dual Celeron system will run MUCH
slower under load, with the posibility of being slower than a
uniprocessor PII due to L2 cache thrashing and extensive memory
contention.

How this maps to a particular users application requires some study,
but I expect that the core OS services that boost the foot print are
used in more applications that the relatively tight inner loops that
dominate gcc's execution profile. Hence my concern that saving $100
for a Dual Celeron, is a very poor tradeoff for most people. And
almost certainly for database, Web and file servers.


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