[Troubleshooting] Q6600 Showing 1.6GHz instead of 2.4?

Hey I recently got a new computer and upgraded it with a new graphics card and it runs perfectly fine but I recently noticed that the speed of the processor is showing ~1.6GHz but the Q6600 should be 2.4GHz, right?

I'm completely new to all of this so please excuse me if this is a completely dumb question. I don't know if it is just showing as 1.6GHz because it's not doing anything right now or if I need to do something to make it reach it's potential. Any help or advice would be greatly appreciated. Here's a screenshot of CPU-Z

http://i.imgur.com/XBgKd.jpg