I was under the impression that the PPro was considered superior architecture
to the PII, even though it's older.
--Adam
-----Original Message-----
From: Robert G. Brown <[EMAIL PROTECTED]>
To: Chris Mauritz <[EMAIL PROTECTED]>
Cc: Adam D. McKenna <[EMAIL PROTECTED]>; [EMAIL PROTECTED]
<[EMAIL PROTECTED]>
Date: Monday, October 05, 1998 12:00 AM
Subject: Re: going from dual P166 to dual PPro
On Sun, 4 Oct 1998, Chris Mauritz wrote:
> > From [EMAIL PROTECTED] Sun Oct 4 13:44:37 1998
> >
> > I got the motherboard for $75 and the two PPro 180's for $100 each..
You're
> > telling me that I can get a dual PII/300 for the same amount? Last I
looked,
> > PII/300's were about $300 each.
>
> Ah. You're using PPro-180's. I just built a dual PII-300 machine
> for about $700, but I used a rather expensive Tyan Tiger motherboard.
> Last I checked, PII-300's were just over $200 each. So if you're
> able to get a cheap board and cheap PPro 180's, perhaps it isn't
> worth it.
Oh, it's "worth" it -- each PII is nearly twice the speed of the PPro
and there are rather a lot of advantages to having a faster CPU compared
to having two slower ones that add up to nearly the same speed. Also,
PPro's are dead technology. Sure they're cheap -- they're cheap for a
reason.
Two configurations that I think are a better idea than a dual PPro right
now include:
a) a dual PII mobo and just ONE PII -- cost, maybe $120 + 260 = $380.
Just about $100 more than you are spending, but in six months you might
be able to add the second PII for just $150-180. Your eventual total
cost would then be just over twice what you'd spend for the dual PPro,
but your eventual performance would be between 3 and 4 times as much.
b) a single Celeron 300A. This costs almost exactly what you plan to
spend -- $100+180 = $280 -- and gives you a 300 MHz cache (albeit a
slightly smaller one). It might be worth it to up the ante $20-30 and
get a BX motherboard with 100MHz memory, as this would more than
compensate for the small clock differential and smaller cache. Although
I'm sure that one could find some specific parallel task mix for which
the dual PPro would be better (something just the right size to fit the
one cache but thrash the other, for example) but on almost any normal
task mix I'd expect the one Celeron processor to outperform a dual 180
PPro without the hassle of parallel programming.
Remember that EACH task you run will run close to twice as fast as it
would on a 180 PPro. Unless ALL of your work is run in near perfect
parallelism and is just the right size to exploit the PPro's slightly
larger cache (on slower memory, with more overhead) you lose with the
dual PPro configuration.
I love smp systems, but I also love optimizing cost-benefit, and it is
very rare indeed that retail hardware on the edge of obsolescence is
worth investing in.
rgb
Robert G. Brown http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567 Fax: 919-660-2525 email:[EMAIL PROTECTED]
