Re: Compare Swarm with Repast

[Nick Collier]

Well I suppose I should post a pseudo-rebuttal so here goes.

On Wed, 2002-08-14 at 05:24, Gary Polhill wrote:
> Just to chime in here, we did a test of the RePast Heatbugs, the 
> JavaSwarm Heatbugs and the (Obj-C) Swarm Heatbugs (on a Sun Blade 1000), 
> and found the Obj-C Swarm heatbugs fastest, the JavaSwarm heatbugs slightly 
> slower, and the RePast heatbugs almost an order of magnitude slower. 
> (For example, in one minute, RePast runs 296 cycles of heatbugs, JavaSwarm 
>  1760 cycles, and Swarm 2017.)

I'm not surprised that the Obj-c version is faster, but by that much!?.
I am surprised that the JavaSwarm version is that much faster. It was
roughly comparable to the repast version last I checked which was
admittedly with an earlier version of javaswarm. I know Marcus has done
lots of work on it since then. I also have anecdotal evidence of users
porting their models from swarm without any problematic loss of speed.

In general, the big speed issue in repast models and with java in
general is the display. With the display minimized (that is, not
updating) I get over 2700 cycles / min for heatbugs on my PIII laptop
running linux. With the display showing and thus updating I get just
over 700. Graphics on Java are slow.

Anyway, I dislike this kind of benchmarking for a several reasons. The
least important of which is that it makes me queasy and usually begins a
fruitless search for something to optimize. The more important reason is
that it rarely tells the whole story. If it takes you, say, twice as
long to code and debug a model before beginning your actual runs, the
actual speed of the runs themselves is much less of a factor and may be
irrelevant. I'm _NOT_ saying that this is the case between repast and
swarm (although I may tell myself this so I can sleep at night) as I
haven't really looked at swarm for a few years, and certainly have never
done any proper comparative benchmarks

Nick

-- 
Nick Collier 
Social Science Research Computing 
University of Chicago 
http://repast.sourceforge.net



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