If your Eclipse is permanently stalling, you cant get your job done, all you see it this annoying beachball then its time to tune it up. There is not too much you can do about it but there are still a few tricks that help.

here they are

Make you eclipse projects smaller

I do not mean you should delete your files but in most cases you dont need all the files in the project. You do not edit pear and zend libraries so put them out of the project folder. Create some symlinks structure so that you use the library on in the development server but they are not in the eclipse project.

Another good idea is to keep files like images, configs, xml data etc separately if you have a lot of them. Public folder with thousands of different files will slow eclipse down as well especially if they contain xml / js / css / html.

Create multiple small PHP projects

If you need zend and you edit it or need to lookup code create separate eclipse project and symlink it in the web server environment.

That way you can close all the projects that are not in use. Closing projects will speed up eclipse PDT the mest!

Turn off autobuild in Eclipse settings

To avoid stalls go to Top menu and make sure that automatic builds are turned off: (Project -> Build automatically)

Buy more RAM

there is nothing better than having lots of ram.

Turn off plugins you are not using

If you are using Eclipse for many languages it is better to have separate installations tailored per platform. This way you get rid of all the plugins code that you do not need. If you work with PHP and Java or Grails etc just get rid of all this junk. Create fresh PHP Eclipse PDT installation and try to keep plugins to minimum. It should also improve stability a lot!

Plugins for silly stuff like SVN and SoapUI ... you do not need them in eclipse. If you need the tool you can always start them up. Usually integration of these tools is not perfect and they increse risk of crashes.

Turn off validators

Go to settings:

Window -> preferences -> validation

Disable validations by checking 'suspend all validations'.

Tweak the Eclipse initialization settings and Java runtime arguments

There are a lot of options to set but its hard to say which will help so you have to experiment with it. It depends how much memory you have etc.

MaxPermSize will not really speed things up its just to store permanent objects like class definitions so giving it 512MB wont help. If you get crash out of perm space then increase in 64MB steps.

This is what im using now.

-startup
plugins/org.eclipse.equinox.launcher_1.1.0.v20100419.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_1.1.0.v20100322-1720
-product
org.eclipse.epp.package.php.product
--launcher.XXMaxPermSize
128M
-showsplash
org.eclipse.platform
--launcher.XXMaxPermSize
128m
--launcher.defaultAction
openFile
-vmargs
-Dosgi.requiredJavaVersion=1.5
-Xms128m
-Xmx512m
-XX:PermSize=128m
-XX:MaxPermSize=128m
-XX:CompileThreshold=5
-XX:MaxGCPauseMillis=10
-XX:MaxHeapFreeRatio=70
-XX:+UseConcMarkSweepGC
-XX:+CMSIncrementalMode
-XX:+CMSIncrementalPacing

It is in Eclipse installation folder in the eclipse.ini file.