Eclipse 32 bits running on 64 bits JVM

Question

After many investigations I can't find a clear answer to the following question: Can Eclipse 32 bits version runs on a 64 bits JVM (of course on a 64 bits windows) ?

I guess the answer should be "NO" but I never worked with 64 bits systems and will be interested to "learn more" of how it work.

Thanks in advance,

Manu

Answer 1

No, that's not possible, because Eclipse's SWT GUI toolkit depends on native libraries (which is the reason there are separate 32 and 64bit version of eclipse in the first place), and you cannot call 32bit native libraries from a 64bit JVM (or, in general, you cannot mix 64bit and 32bit code within the same OS process).

Answer 2

You don't need eclipse to be running as 64-bit unless you intend to use well over 1 GB for the IDE. You can use eclipse to develop 64-bit applications by configuring it to use a 64-bit JVM when running your application.

Note: Java switches between 32-bit and 64-bit transparently (not as simple for native libraries but this can be done also) This means that developing for a 64-bit application looks and smells exactly the same as a 32-bit application. All you get is the warm inner feeling knowing that you are using 64-bit machine code and a bit more memory. Note: using CompressedOops reduces the memory overhead at the cost of some CPU overhead.

If you need to use more than a few GB of memory, that is when 64-bit make a difference, but your code will be exactly the same and no re-compile is required.