Need Help With CPU Please

As you can see in my sig, I have an AMD Athlon 64 3400+ Venice Processor. It's socket 939. When I look it up online it tells me that the core speed for this processor is 2.2 GHz. However, when I run CPU-Z (latest version), my core speed only runs at 1000 MHz. I am running Vista Ultimate. everything else aside from whats mentioned in my sig is stock its a compaq PC. When I start a program or a new firefox window i see the core speed jump to range of 1800-2200 MHz but it quickly settles back to 1000 MHz. Can someone inform me of what the issue could be here. Do I have to enable some kind of setting in the BIOS? It's the stock motherboard so I don't know if I can tweak anything. Thanks in advance.



Link to my CPU: http://www.newegg.com/product/product.aspx?item=N82E16819103023

Disable cnc (cool n quiet) in bios.

Haha yea thanks i googled what you suggested and I found a post somewhere with the same problem and the problem was that my power option was set to balanced instead of full performance. Thanks for the help boss its now at 2200 MHz. Didnt have to mess with BIOS.