Monitoring your Ram and making sure you have enough!
Activity Monitor is a very useful tool in ensuring that the quantity of Ram you have is not what is slowing everything down. With the powerful computers we have today, the two things that can be a huge slowdown is an hard drive without enough free space and not enough Ram. You should always have at least 10% (or 10 GB for smaller hard drives) of free space. Not enough Ram also slows everything down, because the OS will constantly swap data to the hard drive and the hard drive is slow. Here is what Activity Monitors tells you about your Ram:
There are four categories: Free, Wired, Active and Inactive. What is actually being used now is Wired and Active. The sum of Free and Inactive is what is unused. You might want to consider having enough Ram so that you don't have to use the Inactive memory, because Inactive memory often adds a lot of speed. What is stored in Inactive memory is the data of an application that was running previously. That is why it is always faster to load an application the second time. This is exactly what Apple does when presenting their software. They load it once, quit it, and load it again in front of the camera. It looks much snappier the second time because everything is still stored in the Ram. To really understand if you need more Ram, you'll have to look at the "Page outs". Page outs are data that had to be transferred to the hard drive because the OS ran out of Ram. It is normal to have some Page outs if your computer has been running for a while, because the quantity of Page outs is only reseted when you restart. The best way of seeing what is going on is to leave Activity Monitor running and watch it while working. When you have many applications running and you see that it is accumulating a lot of Page outs, it is safe to say that more Ram would probably speed things up a lot!