Vous lancez votre Eclipse via

C:\eclipse-jee-ganymede-SR1-win32\eclipse\eclipse.exe -clean -data "C:\Documents and Settings\monUser\workspace"

Modifier votre initial fichier eclipse.ini :

-showsplash
org.eclipse.platform
--launcher.XXMaxPermSize
256M
-framework
plugins\org.eclipse.osgi_3.4.2.R34x_v20080826-1230.jar
-vmargs
-Dosgi.requiredJavaVersion=1.5
-Xms40m
-Xmx512m

En

-showsplash
org.eclipse.platform
--launcher.XXMaxPermSize
256M
-framework
plugins\org.eclipse.osgi_3.4.2.R34x_v20080826-1230.jar
-vmargs
-Dosgi.requiredJavaVersion=1.5
-Xms40m
-Xmx512m
-XX:PermSize=128m
-XX:MaxPermSize=256m

Au besoin préciser la version java utilisée avec :

-vm "C:\Program Files\Java\jdk1.6.0_10\bin\javaw.exe"

Utiliser une ancienne jre, serait :

-vm "C:\Program Files\Java\jdk1.5.0_15\bin\javaw.exe"

Les options non standards de java :

C:\Documents and Settings\monUser>java -X
   -Xmixed           mixed mode execution (default)
   -Xint             interpreted mode execution only
   -Xbootclasspath:<directories and zip/jar files separated by ;>
                     set search path for bootstrap classes and resources
   -Xbootclasspath/a:<directories and zip/jar files separated by ;>
                     append to end of bootstrap class path
   -Xbootclasspath/p:<directories and zip/jar files separated by ;>
                     prepend in front of bootstrap class path
   -Xnoclassgc       disable class garbage collection
   -Xincgc           enable incremental garbage collection
   -Xloggc:<file>    log GC status to a file with time stamps
   -Xbatch           disable background compilation
   -Xms<size>        set initial Java heap size
   -Xmx<size>        set maximum Java heap size
   -Xss<size>        set java thread stack size
   -Xprof            output cpu profiling data
   -Xfuture          enable strictest checks, anticipating future default
   -Xrs              reduce use of OS signals by Java/VM (see documentation)
   -Xcheck:jni       perform additional checks for JNI functions
   -Xshare:off       do not attempt to use shared class data
   -Xshare:auto      use shared class data if possible (default)
   -Xshare:on        require using shared class data, otherwise fail.