Re: Is Java 1.6 number crunching slower than 1.5?

From:

Robert Klemme <shortcutter@googlemail.com>

Newsgroups:

comp.lang.java.programmer

Date:

Sat, 15 Aug 2009 13:36:44 +0200

Message-ID:

<4A869DCC.1050803@googlemail.com>

On 15.08.2009 13:18, Tom Anderson wrote:

On Fri, 14 Aug 2009, Kevin McMurtrie wrote:

I pulled out a few bits of code and patched it together so a test case
does the same kind of math as the real deal. (Don't be a style freak -
it's demo fragment squished to fit in a Usenet posting.)

Machine:
MacOS X 10.5.8

Darwin desktop.pixelmemory.us 9.8.0 Darwin Kernel Version 9.8.0: Wed Jul
15 16:55:01 PDT 2009; root:xnu-1228.15.4~1/RELEASE_I386 i386

---------------
Java 1.5

Version:
java version "1.5.0_20"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_20-b02-308)
Java HotSpot(TM) 64-Bit Server VM (build 1.5.0_19-137, mixed mode)

Options: -d64 -mx2G

Output:
Millis: 5979.04
Millis: 5984.168
Millis: 5987.027
Millis: 5979.992
Millis: 5953.974

---------------
Java 1.6

Version:
java version "1.6.0_15"
Java(TM) SE Runtime Environment (build 1.6.0_15-b02-215)
Java HotSpot(TM) 64-Bit Server VM (build 14.1-b02-87, mixed mode)

Options: -d64 -mx2G

Output:
Millis: 6943.407
Millis: 6937.324
Millis: 6917.524
Millis: 6931.662
Millis: 6917.065

Zoinks. I'd suggest filing a bug report with Sun - that is a substantial
performance regression.

Maybe Sun optimized the JVM in other areas (e.g. IO bandwidth and
throughput) which are more important for the average server application
today. Maybe the optimization kicks in later. I am not convinced that
what we have seen constitutes a bug.

Kind regards

robert

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