I concur, but with conditions.  The number of agents that can comfortable reside on a cpu depends on both the agent complexity and the amount of memory on the cpu.  EpiSims agents are relativly complex,  yet we regularly run 1.4 million agents per cpu on one of our dual-Opteron clusters where each dual-cpu node has about 4 GB of memory.  If we are doing other things in the simulation besides just moving the agents around and allowing disease to propagate we require more cpus.  For example, we sometimes collect person-person contact pattern dendograms during a run, which quickly eats lots of memory, even though we cache and flush the growing dendogram frequently.

--Doug
--
Doug Roberts, RTI International
[EMAIL PROTECTED]
[EMAIL PROTECTED]
505-455-7333 - Office
505-670-8195 - Cell

On 10/5/06, Russell Standish <[EMAIL PROTECTED]> wrote:
I concur. 1 million agents on a single CPU is usally feasible in
C/C++. You do need to make sure agent interactions are local though,
as otherwise doing the full n^2 interactions will kill any simulation.

Cheers

On Sun, Oct 08, 2006 at 11:04:25PM -0600, Marcus G. Daniels wrote:
> Owen Densmore wrote:
> >    - ABM: We'd love to be able to run really large simulations (the
> > city of Santa Fe, for example) with up to 250,000 agents.
> 250,000 should not be a problem on one CPU.   Profile the code, natively
> compile and optimize the crucial bits.  Write core loops in C if you
> have to.  Buy a copy of Intel VTune to really see what is going on to
> please or displease the processor.   I've run half a million agents in
> Swarm on an ordinary Athlon 64 in under 2GB.
>
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A/Prof Russell Standish                  Phone 0425 253119 (mobile)
Mathematics
UNSW SYDNEY 2052                         [EMAIL PROTECTED]
Australia                                http://parallel.hpc.unsw.edu.au/rks
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FRIAM Applied Complexity Group listserv
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