Websphere and dual cpus

[Brahim Bakayoko]

Hi all,
Does anyone knows how websphere performs on a dual cpus machine?
Will the application threads be distributed properly to each cpu or will websphere rely on the OS for managing multitasking?
The planned setup is Windows 2003 server and Websphere application server 5.0.2 or 5.1.
Also, only one instance of the server will run.
[ April 13, 2004: Message edited by: Brahim Bakayoko ]

[Kyle Brown]

The JVM automatically manages threads across both processors. WebSphere does not need to get involved in this.
Kyle

[Brahim Bakayoko]

Thanks Kyle!
My question now is, is the effective usage of both cpus built into the jvm or does the jvm still has to rely on the OS cpu management?
I have worries that the OS will see the jvm as a single process and only set it up to use only one cpu. Is that the case?
The biggest thing is that I will be using windows 2003. In windows, you often have to set the process affinity of a particular application to one of the cpu manually as windows does poor multitasking management.

[Kyle Brown]

No, that's not the case. The JVM will use both processors correctly, even on Windows. It's built into the JVM, which does use OS resources, but very low level ones.
Trust me, it works. I've been doing this on multi-CPU (32-cpu in some cases) windows boxes for years.
Kyle

[Brahim Bakayoko]

Good to hear that.
Thanks a bunch for the help.

[serge masse]

Kyle,
Do you know if the memory model problems that were corrected in the new Java language specifications used for J2SE 5.0 had previously been corrected by IBM in the JVM in these older versions of WAS (5.x) or if these memory model defects are also present in these IBM JVMs?

thanks,