[Beowulf] recommendations for cluster upgrades

[Rahul Nabar]

I'm currently shopping around for a cluster-expansion and was shopping
for options. Anybody out here who's bought new hardware in the  recent
past? Any suggestions? Any horror stories?

We've been using Dell SC1435's with Quad-Core AMD 2354 Opterons @
2.2GHz. 16 Gig RAM.

Any new-cutting edge stuff I ought to be asking my vendors to put into
the quotes? I already have gigabit bonded backbones and don't think we
have the financial muscle to upgrade to Myrinet or Infiniband yet. In
the interest of homogeniety and not wanting to have dual trees of
executibles I might be tempted to stick with AMDs unless there is
compelling temptation otherwise.

I am already looking at the CPU benchmarks on the Intel/AMD websites
but they can sometimes be misleading / misrepresenting other than the
obvious glaring conflict of interest. I rather trust first-hand
anecdotal evidence from you guys actually administering them for
scientific applications. Unless there is a good third party, relevant
database?

For some reason the top500 sublists seem skewed to prefer the Intel
Xeons. Why so few Opterons or any other AMD hardware? Just curious if
this is driven by technological inferiority of only a marketing
effect. My vendor seems to be trying to steer me towards an Intel
Nehalem or Clovertown for whatever reasons good or bad.

Ultimately of course, it might be best if I just got to benchmark my
very own application on these CPUs before I bought them. But that's
just wishing I guess!

-- 
Rahul