Configuring eclipse/java to boost the performance to the fullest

Question

I have a windows pc with 64 bit OS (windows 7 Enterprise) and 8 GB of RAM. I want to run a heavy java program on eclipse and I would like to allocate as much of the PC resources only to eclipse/JVM to boost the performance.

By the way, in two different runs of the same program, it took 33 mintues in one and 15 hours in the other. That's a very big difference which I do not know what configuration change (if any) caused this deterioration in the performance.

Could you please help me to Configure it properly?

Answer 1

In eclipse.ini (in the main folder of eclipse) there is a bunch of parameters that should help you to configure the amount of memory. At the end of the file should be sth like this:

-vmargs
-Xms1024m 
-Xmx2048m (max heap)
-Xss1m    (stack)

You can add as many parameters as you need. All of them must be after the line

-vmargs

You can find more JVM parameters here

Answer 2

also you can allocate memory for Java with this way:

• Type Java inside the Search Control Panel box.
• Click the Java icon that pops up.
• Click view
• Make sure to get the x64 version if you have a 64-bit OS.
• Change Runtime Parameters, put '-Xmx1024m' for exemple

Change it depending on how much RAM you have, it is recommend you use 256/512/768/1024/1536/2048. For 32-bit Operating Systems 768M is recommended. If you have 64-bit, or that doesn't work, continue to try the following:1024m, 1536m, 2084m

hope that help.