[Beowulf] Thought that this might be of interest

[Jeffrey B. Layton]

Joshua Baker-LePain wrote:
> On Sun, 5 Nov 2006 at 8:54am, Joe Landman wrote
>
>> Initial benchmarks (2.6 GHz clock) put it at about 17% faster than 
>> Opteron 275 and Woodcrest 5150 (2.66 GHz) on a GAMESS test we use 
>> (1h41m for Woodcrest and 275, and 1h26m for this unit).
>
> I'd be very interested to see any application benchmarks you've run.  
> In my testing <http://www.duke.edu/~jlb17/optxeon.pdf>, Xeon 5140s 
> blow the doors off Opteron 270s -- moreso than the clockspeed 
> difference would indicate -- in almost all my benchmarks.  I was 
> leaning the Xeon way for any new purchases, but I haven't had a chance 
> to test the new Opterons yet.
It's fairly well known that Woodcrest is better than Opteron on
LS-Dyna. The results at Topcrunch also support this. I haven't
looked too closely at _why_ it's faster. Is it the bigger cache?
Is it a better chip? I'm not sure.

I'm also not sure if LS-Dyna is built with the Intel compilers or
not. This will also have an impact on performance since you have
to _dumb-down_ the compile options to get it to run on Opteron
(I mentioned this to Joe Landman, but for everyone's edification,
here's a link:

http://www.swallowtail.org/naughty-intel.html

that discusses how to fix the resulting Intel binaries to run
better on Opteron or to patch the compiler itself).

I haven't seen the Matlab results before. Those are interesting.
Can you explain the benchmarks a bit more? Is it the stock Matlab
or did you substitute the BLAS library? That might make a
difference.

Thanks!

Jeff