If you are using 4 GB Ram, the following will help you to increase the speed of the eclipse
Goto the Folder where eclipse.exe is located.
Open the eclipse.ini
-startup
plugins/org.eclipse.equinox.launcher_1.2.0.v20110502.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_1.1.100.v20110502
-product
org.eclipse.epp.package.jee.product
--launcher.defaultAction
openFile
--launcher.XXMaxPermSize
256M
-showsplash
org.eclipse.platform
--launcher.XXMaxPermSize
256m
--launcher.defaultAction
openFile
-vm
C:/Program Files/Java/jdk1.6.0_21/bin/javaw
-vmargs
-Xmn128m
-Xms1024m
-Xmx1024m
-Xss2m
-XX:PermSize=128m
-XX:MaxPermSize=128m
-XX:+UseParallelGC
For other than 4 GB, read the following article
http://madhucm.wordpress.com/2007/12/19/tuning-eclipse-performance-and-avoiding-outofmemoryexceptions/