I’m presently running a jogl app in jdk 1.6 on top of 32 bit linux (Fedora Core 6) and want to know if I will see any difference in the jogl app if I run jdk 1.6 on top of x_64 linux.
I don’t think so. There are various tradeoffs between x86 and x86_64; there are more machine registers available in 64-bit mode, but all pointers (including Java object references) become twice as large in the 64-bit Java HotSpot VM. In general for memory-intensive applications there is currently about a 10% performance reduction when running the 64-bit JVM compared to the 32-bit one.
Unless you really need more than 4 GB of addressable space in your application, you’re probably better off sticking with the 32-bit JVM.
So if I had an app that wanted to use a Java heap size of greater than 4GB I would need the 64 bit JVM’s. The 32 bit JVM wouldn’t work. Yes?
That’s correct. You’d get an error during initialization of the JVM because it wouldn’t be able to support your -Xmx setting.