If you have a Mac that seems to have suddenly slowed down here are some Tips that may speed it up again. Activity Monitor shows you just what your Mac is doing, so you can diagnose why it’s slowed down.
How to find out how much of your Hard Drive is being used; and what to do if you’re running out of space.
RAM is the working space for your computer. The applications all share it, but more RAM might make your computer work better.
Use the Real Memory column in Activity Monitor to show which applications are using up all the RAM.