Re: OS400 JVM performance

["Paul Morgan" <pmorgan@xxxxxxxxxxxxxx>]

Peter,

It was interesting to read Andy's comments about JVM performance.  I'm no
expert on JVM performance but I did just do a little looking at the
specjbb2000 benchmark.  The IBM iSeries benchmark
(http://www.spec.org/osg/jbb2000/results/res2004q4/jbb2000-20041012-00259.ht
ml) is about eighth on the list for performance results.  The spec say it
does test garbage collection (http://www.spec.org/jbb2000/docs/faq.html#Q7)
and that garbage collection does affect the results
(http://www.spec.org/jbb2000/docs/faq.html#Q38).  I don't see IBM using the
mentioned input.forcegc property (which will move garbage collection to
between warehouse run in the test) but it's possible they did that.  I do
see some option for (os400.pool.size 4096) and (os400.aggressive.heap) in
the IBM results which might be tweaks for garbage collection.  The spec
mentions a large heap reducing the need for garbage collection.

Is this Specjbb200 benchmark what Andy's referring to when he talks about
IBMs performance benchmarks not being worth much?

thanks,
Paul