RE: iSeries JVM version

["Urbanek, Marty" <Marty_Urbanek@xxxxxxxxxxxx>]

Joe,

I have no solid numbers to give you but we are finding the i5 box helped our 
Java apps a bunch. Now mind you, we have like 8 times the CPU and memory we had 
before and we are running about 6 times faster. 

After yesterday's conversation, I ran some stuff on JDK 1.3.1 versus 1.4.2 on 
our 550. Many of the tests are I/O, DB and communications dependent, so it is 
not at all a "CPU intensive" test suite. However certain tests are more compute 
intensive than others. Looking at the whole bunch overall, I found little 
difference between 1.3.1 and 1.4.2. My thinking was that if there was indeed 
some major (3x, 8x, 11x) improvement just due to the JDK, that I would be able 
to see it in certain tests. I did not find anything of that magnitude, although 
maybe a couple percent better in a couple spots.

I think the new hardware is just that much faster. I would get the 520 versus 
the 810. I think these POWER5 chips are helping  Java big time on iSeries. You 
should give some thought to that sandwich. For some reason "Blairwich" has a 
bad ring to it...

-Marty

--------- original message ---------------------

date: Mon, 24 Jan 2005 11:35:12 -0600
from: "Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>
subject: RE: iSeries JVM version

3x isn't 11x.  And DE to JIT isn't another 3.5x.  So where did all this
performance come from?  

The fact that it's one of the fastest machines in the world is actually
a shocker, and it's certainly NOT the perception in the world at large.

Thought exercise: I'm running a 2002 model 270 at V5R1.  When I move to
a model 520 or a model 810 at V5R3, will I see an 11-fold increase in
performance?  If so, I will name my next child after you.  Heck, if it's
just 5x, I'll name a sandwich after you.

Joe