[TriLUG] 16+ GB RAM PC advice

[Ed Hill]

Hi Carlos,

For large memory systems (>4GB RAM) the Xeons are awful.  Instead, you
should consider Opterons, Itaniums, or other hardware.  We have a number
large-memory systems within our network

  http://acesgrid.org/technical_blueprint.html
 
including:

  + Dell dual-Itaniums w/ 16GB RAM
  + dual-Opterons: (mostly Tyan 2885 MB w/ 16GB RAM)
  + an Altix 350 w/ 16 CPUs and 32GB RAM

and they perform *far* better than the Xeons on predominantly memory-
bandwidth-limited scientific applications.

Dual (up to 16GB RAM) and quad (up to 32GB RAM) Opteron systems can be
purchased and/or assembled for a few thousand dollars and they scale
*remarkably* well.  I'm very fond of our Opterons.  We see almost linear
(that is, per-CPU) speed-ups with many applications including our main
ocean/atmospheric modeling software.  And Linux (we use both Fedora Core
2 for x86_64 and RHEL v3 for x86_64) runs quite nicely on the Opterons.

For more than 32GB RAM, you'll have to look into SGI Altix or other
high-end hardware.  For truly huge simulations it is often best to get
time at a center such as:

  http://www.ncsc.org/
  http://www.psc.edu/

rather than trying to buy your own.  As an academic, you can usually get
grants of computing time on their (often huge) systems quite easily.

Good luck with your simulations!

Ed

-- 
Edward H. Hill III, PhD
office:  MIT Dept. of EAPS;  Rm 54-1424;  77 Massachusetts Ave.
             Cambridge, MA 02139-4307
emails:  eh3 at mit.edu                ed at eh3.com
URLs:    http://web.mit.edu/eh3/    http://eh3.com/
phone:   617-253-0098
fax:     617-253-4464