RE: FDS4 Beta Test

[Charles Bouldin <charles.bouldin@nist.gov>]

>Sender: "Miller Hannah" <millerhannah@london.hoarelea.com>
>Subject: RE: FDS4 Beta Test
>
>
>Kevin
>
>I am just buying a new computer. Is it worth buying a 64bit computer. Will
>FDS run much faster?
>
>Miller


If I can throw in my $0.02....I have been trying to figure out the 
"64 bit" question myself. The first thing to say is that it is too 
early to reach final conclusions! However, I think that the 64 bit 
desktop machines are all likely to give significant improvements in 
FDS speed.

Some hard data: I have a dual processor 2.0 ghz chips G5 Macintosh. 
This runs FDS4 at a speed equivalent to a dual processor 4.2 to 4.8 
ghz Pentium 4 (if such a thing existed). I have built and installed 
MPI on this machine and just completed a parallel processing run that 
used both cpu's. It took 59 hours on the dual processor Mac and 107 
hours on a dual processor 2.4 ghz Pentium.

I expect, but cannot yet demonstrate, that similar improvements will 
be possible with itanium or Athlon64 based machines. Two major 
unknowns at this time are the operating system, either Linux64 or a 
64-bit version of XP(?), and the existence of good 64 bit F95/C 
compilers.

We don't yet have any 64-bit PC hardware that is analogous to the 64 
bit Mac. The Mac also benefits from an existing IBM fortran compiler 
for the G5 chip. The hardware/OS/compiler troika has to be tested in 
its entirety on each platform before we can reach conclusions about 
which 64 bit system is "best" for FDS runs.

At this point, a dual processor G5 Mac looks like a very good 
platform to run FDS. MAJOR CAVEAT: Smokeview does not yet run on the 
G5, but I am working on porting it. You can run FDS on the Mac and 
view .smv files on a PC, just as we do with the Linux/PC combination 
of calculation/viewing.

I'm giving a presentation at Interflam that will discuss the parallel 
processing version of FDS, and will get into issues of Linux cluster, 
vs. Windows cluster, vs. PowerMac clusters. Each of these 
configurations has some things to recommend it. Which is best for any 
particular group/lab/office/problem depends on case specific details.

I would be interested in hearing from anyone who is running FDS on an 
itanium or Opteron or Athlon64 system. Probably this is something 
that could be discussed at length off-list and then we could post 
conclusions back to the list.