Eclipse 3.5 (Galileo) on OS X: Speeding it up

I recently started using Eclipse on OS X and it was so unresponsive, it was almost unusable. Switching tabs was slow, switching perspectives was hella slow. I searched around the web for a solid hour for how to make it faster and finally found the solution. Maybe someone can use it.

My machine is running OS X 10.5, and I have 2 GB of RAM. (This is important because the solution requires messing with how Eclipse handles memory. If you have a different amount of RAM, these numbers may not work and you’ll need to fiddle with them.)

  • Save your work and quit Eclipse.
  • Open the Eclipse application package by right-clicking (or Control-clicking) on and select “Show Package Contents.”
  • Navigate to Contents→MacOS→, and open “eclipse.ini” in your favorite text editor.
  • Edit the line that starts with -“XX:MaxPermSize” to say “-XX:MaxPermSize=128m”.
  • Before that line, add a line that says “-XX:PermSize=64m”.
  • Edit the line that starts with “-Xms” to say “-Xms40m”.
  • Edit the line that starts ith “-Xmx” to say “-Xmx768m”.
  • Save & relaunch Eclipse.

Worked like a charm for me.