How can I give eclipse more memory than 512M?

I have following setup, but when I put 1024 and replace all 512 with 1024, then eclipse won't start at all. How can I have more than 512M memory for my eclipse JVM?

-startup
plugins/org.eclipse.equinox.launcher_1.0.201.R35x_v20090715.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_1.0.200.v20090519
-product
com.springsource.sts.ide
--launcher.XXMaxPermSize
512M
-vm
C:\Program Files (x86)\Java\jdk1.6.0_18\bin\javaw 
-vmargs
-Dosgi.requiredJavaVersion=1.5
-Xms512m
-Xmx512m
-XX:MaxPermSize=512m

I've had a lot of problems trying to get Eclipse to accept as much memory as I'd like it to be able to use (between 2 and 4 gigs for example).

Open eclipse.ini in the Eclipse installation directory. You should be able to change the memory sizes after -vmargs up to 1024 without a problem up to some maximum value that's dependent on your system. Here's that section on my Linux box:

-vmargs
-Dosgi.requiredJavaVersion=1.5
-XX:MaxPermSize=512m
-Xms512m
-Xmx1024m

And here's that section on my Windows box:

-vmargs
-Xms256m
-Xmx1024m

But, I've failed at setting it higher than 1024 megs. If anybody knows how to make that work, I'd love to know.

EDIT: 32bit version of juno seems to not accept more than Xmx1024m where the 64 bit version accept 2048.

EDIT: Nick's post contains some great links that explain two different things:

• The problem is largely dependent on your system and the amount of contiguous free memory available, and
• By using javaw.exe (on Windows), you may be able to get a larger allocated block of memory.

I have 8 gigs of Ram and can't set -Xmx to more than 1024 megs of ram, even when a minimal amount of programs are loaded and both windows/linux report between 4 and 5 gigs of free ram.

Here is how i increased the memory allocation of eclipse Juno:

I have a total of 4GB on my system and when im working on eclipse, i dont run any other heavy softwares along side it. So I allocated 2Gb.

The thing i noticed is that the difference between min and max values should be of 512. The next value should be let say 2048 min + 512 = 2560max

Here is the heap value inside eclipse after setting -Xms2048m -Xmx2560m:

Care and feeding of Eclipse's memory hunger is a pain...

• http://www.eclipsezone.com/eclipse/forums/t104307.html
• https://bugs.eclipse.org/bugs/show_bug.cgi?id=188968
• https://bugs.eclipse.org/bugs/show_bug.cgi?id=238378

More or less, keep trying smaller amounts til it works, that's your max.

You can copy this to your eclipse.ini file to have 1024M:

-clean -showsplash
org.eclipse.platform
--launcher.XXMaxPermSize
256m
-vmargs
-Xms512m
-Xmx1024m
-XX:PermSize=128m
-XX:MaxPermSize=256m 

I don't think you need to change the MaxPermSize to 1024m. This works for me:

-startup
plugins/org.eclipse.equinox.launcher_1.0.200.v20090520.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_1.0.200.v20090519
-product
org.eclipse.epp.package.jee.product
--launcher.XXMaxPermSize
256M
-showsplash
org.eclipse.platform
--launcher.XXMaxPermSize
256m
-vmargs
-Dosgi.requiredJavaVersion=1.5
-Xms256m
-Xmx1024m
-XX:PermSize=64m
-XX:MaxPermSize=128m

While working on an enterprise project in STS (heavily Eclipse based) I was crashing constantly and STS plateaued at around 1GB of RAM usage. I couldn't add new .war files to my local tomcat server and after deleting the tomcat folder to re-add it, found I couldn't re-add it either. Essentially almost anything that required a new popup besides the main menus was causing STS to freeze up.

I edited the STS.ini (your Eclipse.ini can be configured similarly) to:

--launcher.XXMaxPermSize 1024M -vmargs -Xms1536m -Xmx2048m -XX:MaxPermSize=1024m

Rebooted STS immediately and saw it plateau at about 1.5 gigs before finally not crashing

Configuring this worked for me: -vmargs -Xms1536m -Xmx2048m -XX:MaxPermSize=1024m on Eclipse Java Photon June 2018 > Running Windows 10, 8 GB ram and 64 bit. > You can extend -Xmx2048 -XX:MaxpermSize= 1024m to 4096m too, if your computer has good ram.Mine worked well.