Advised JVM for amd64: 32- or 64 bit ?

I was wondering what the advised JVM architecture is for a 64bit Linux platform. I'm always using the 64bit JDK for the IDE. Because it seemed natural to me. Even knowing the pointer size is double compared to the 32bit JVM.

Untill today I ignored this also comes with a CPU performance impact. Unless using compressed pointers, etc, etc...

So, what performs better for IntelliJ ? 32- or 64 bit JVM's ?

TIA !!!

Jan

2 comments

On Wed, 30 Nov 2011 21:04:02 MSK, Jan Goyvaerts
<no_reply@jetbrains.com> wrote, quoted or indirectly quoted someone
who said :

>I was wondering what the advised JVM architecture is for a 64bit Linux platform. I'm always using the 64bit JDK for the IDE. Because it seemed natural to me. Even knowing the pointer size is double compared to the 32bit JVM.
>
>Untill today I ignored this also comes with a CPU performance impact. Unless using compressed pointers, etc, etc...
>
>So, what performs better for IntelliJ ? 32- or 64 bit JVM's ?

Intellij uses its own private 1.6 JVM.  What works best for your own
apps has nothing to do with IntelliJ.  It runs your apps with your 1.7
JVM.

You can argue which SHOULD work better or you can do a test.

The things in favour of 64 bit -- more registers, more data processed
per op.  Big address space can handle large ram-resident problems.

The thing in favour of 32-bit -- more compact code so more likely to
be in cache, pointers are smaller, data more compact so more likely to
be in RAM cache.  same app uses less RAM.

For 64 bit to work well, you need lots of RAM and lots of RAM cache.

When it matters, you can run it both ways and see which works better.
Which works better may change if your machine is busy with lots of
other work.

You don't have to reconfigure IntelliJ to do the benchmark. Just run
your benchmarks outside IntelliJ.
--
Roedy Green Canadian Mind Products
http://mindprod.com
For me, the appeal of computer programming is that
even though I am quite a klutz,
I can still produce something, in a sense
perfect, because the computer gives me as many
chances as I please to get it right.

0

I'll have a try then. Maybe I'll see the difference. :-)

Anyway, the IntelliJ script idea.sh is really looking for an installed jdk to run. So no internal jdk. At least on Linux. I can't tell for windows or Mac.

0

Please sign in to leave a comment.