Very slow Eclipse 4.2, how to make it more responsive?

Question

I'm using Eclipse PDT on a rather large PHP project and the IDE is almost unusable. It takes nearly 30 seconds to open a file, and other actions, like selecting a folder in the file explorer, editing some text, etc. are equally slow.

I followed various instructions to speed it up but nothing seems to work. This is my current eclipse.ini file. Any idea how I can improve it?

-startup
plugins/org.eclipse.equinox.launcher_1.3.0.v20120522-1813.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_1.1.200.v20120522-1813
-showsplash
org.eclipse.platform
--launcher.XXMaxPermSize
256m
--launcher.defaultAction
openFile
-vmargs
-server
-Dosgi.requiredJavaVersion=1.7
-Xmn128m
-Xms1024m
-Xmx1024m
-Xss2m
-XX:PermSize=128m
-XX:MaxPermSize=128m
-XX:+UseParallelGC

System: Eclipse 4.2.0, Windows 7, 4 GB RAM

Answer 1

It looks like Eclipse in silence have created a fix and announced it in all secracy through their wiki (!). It seems to alleviate the problems for me at least; though I have not tested it in length yet.

See http://wiki.eclipse.org/Platform_UI/Juno_Performance_Investigation

Basically you should install the "Juno SR1 Patches/Eclipse UI Juno SR1 Optimization" from their 4.2 update site: http://download.eclipse.org/eclipse/updates/4.2

Bug-tracking for this optimization: https://bugs.eclipse.org/bugs/show_bug.cgi?id=394588