Natural Science Forum / Physics / Particle Physics / May 2006

CPU systems for portables must have low power (batteries) and heat
(crappy internal cooling) dissipation.  If you need serious iron you
cannot get it as a portable.  

http://www.abs.com/index.asp
Awesome bang for the buck

If it must be a portable, look at ABS Mayhem portables for
benchmarks.  Go for cheap sound and graphics cards.  You are pretty
much stuck with Intel Centrino CPUs given power consumption problems
for high-end portables.  Look at the benchmarks.  Try some
configurations with the on-line builder to control price.

Things will massively change post-July.

In May 2006, AMD FX-60 and X2 4800+ dual core CPUs beat the snot out
of anything Intel Pentium can imagine.  FX-57 for single core CPU.
Pentiums are particularly bad at matrix algebra and memory management
(and good at media compression.  Are you making movies?).  AMD memory
management is integrated on-CPU at full CPU frequency.  Intel runs on
mobo 533 MHz.  (CPU frequency is irrelevant.  Throughput/cycle is
relevant.)

http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2668
http://www.extremetech.com/article2/0,1697,1909488,00.asp

Corsair low-latency RAM on an ASUS mobo is a great AMD install for
Socket-939.  If you want serious muscle you are looking at $3K for a
desktop PC.  By July 2006 AMD will have scrapped Socket-939 for
Socket-AM2.  Things will be faster still and Socket-939 hardware will
drop in price.  Socket-AM2 requiring registered RAM will munch much
folding green.

The AMD FX-60 at 100% sustained crunch warms to about 55 C.  The Intel
Pentium 955 Extreme Edition will routinely give you temp excursions
past 80 C, triggering its automatic frequency downgrade.  Whatever
Intel promises you for CPU frequency, you won't get it when you really
need it.

Does your software support dual-core chips?  Your OS?  If they support
64-bit operation (e.g., Knoppix-64 LIVE!) you would be mad to go
Intel.

First off, laptops are not the most power for a given price.
For that you would need something like a dual core Pentium.
Also, how memory intensive are the computations?
For reference a single core Pentium running at 2GHz can sustain a
throughput of around 500 MFLOPS.

Any idea how much power is needed to execute the above progs in
reasonable time? Bear in mind that custom computers that do this sort of
thing (eg lattice QCD) are typically hundreds or thousands of times faster.
http://www.icsa.inf.ed.ac.uk/research/groups/hase/projects/qcd/

Getting back to the specs of laptops, go for the fastest clock speed and
the most RAM.

Dirki

Big advantage for scientific computing is a 64-bit CPU like AMD Turion
64. A computer should have at least 1GB RAM. They are priced nowadays
from about $800.

You will need to upgrade OS to 64-bit at extra cost and find 64-bit
Mathematica and so on.

The best brand is one you like - touch the keyboard, look at the
screen, size, weight.

Try something from Hypersonic (hypersonic-pc.com) or SGI (sgi.com).
Gaming machines and graphic design ones usually have enough power to
handle scientific work.

If you are only using off-the-shelf software, then buy the system that
the software is supported on.

If you are doing coding, then you'll probably want to run Linux or
something else without much OS computing overhead, and Linux runs on a
variety of hardware platforms.

Do a google search for "high energy physics computing farms" and see
what the pros have been buying in stacks and stacks to handle petabytes
of data.