64-Bit Websphere on AIX

Greetings.

We are currently evaluating some of the infrastructure we would use as part of a JDE 8.0 -> 9.0 upgrade. Our company uses AIX 64-bit as the standard for websphere. Per the MTR's it looks like Oracle is only supporting 32-bit websphere on AIX. I have a few questions on this...

Is there anyone else out there using websphere on AIX? Are you using 32-bit or 64-bit? If 32-bit, did you make that decision solely based on the Oracle support?

It seems like 64-bit websphere is supported on almost all other platforms... linux, hp-ux, i-series, windows, etc... Does anyone know why Oracle is not supporting 64-bit websphere on AIX?

Thanks for your feedback!

I think you might have read this wrong.

WAS 64 bit is NOT supported on any platform.
WAS 32 bit is supported on ALL platforms.

All versions of WAS use IT4J (IBM Technology for Java JVM). Only the 32-bit version is supported.

On 64 bit platforms WAS 32 bit runs in a compatability environment.

This is the same for all HP-Unix, SUn Solaris, AIX, Red Hat Linux, Oracle Linux, Windows and OS/400 environments - simply a 32-bit app running on a 64-bit platform with a 32-bit JVM.

Not that it really matter's but JDE runs just fine with 64-bit WAS and a 64-bit JVM.

A 64-bit JVM won't necessarily run any faster than a 32-bit JVM.

How many useers are you looking at? What are hte other details of your environment?

Colin

Here's a reference on iy and there are many more but generally a 64-bit JVM requires more meory and is slower than the same App running under a 32-bit JVM.

Still sure you wanna switch?

http://www.oracle.com/technetwork/java/hotspotfaq-138619.html#64bit_description

What are the performance characteristics of 64-bit versus 32-bit VMs?

Generally, the benefits of being able to address larger amounts of memory come with a small performance loss in 64-bit VMs versus running the same application on a 32-bit VM. This is due to the fact that every native pointer in the system takes up 8 bytes instead of 4. The loading of this extra data has an impact on memory usage which translates to slightly slower execution depending on how many pointers get loaded during the execution of your Java program. The good news is that with AMD64 and EM64T platforms running in 64-bit mode, the Java VM gets some additional registers which it can use to generate more efficient native instruction sequences. These extra registers increase performance to the point where there is often no performance loss at all when comparing 32 to 64-bit execution speed.
The performance difference comparing an application running on a 64-bit platform versus a 32-bit platform on SPARC is on the order of 10-20% degradation when you move to a 64-bit VM. On AMD64 and EM64T platforms this difference ranges from 0-15% depending on the amount of pointer accessing your application performs.

Thanks for the information. We have a small userbase of about 50 users that are all onsite. We aren't looking at 64-bit for any performance reasons. We are looking at it because our company currently only supports 64-bit WAS environments. So going on 64-bit would mainly be an exercise in keeping out technology consistent.