Have you played with the Core center program? I have that same motherboard and I have found out a couple of things.
1. If you set your memory timings correctly, you can change your system speed to turbo from fast. Auto settings tend to make my system unstable, when I set it to turbo.
2. Don't bother with the Dynamic overclocking in the bios, just leave it at 200Mhz and no overclocking. This might overclock your system even when you are doing regular processing tasks like watching a movie or encoding, when you dodn't really need it to overclock.
3. You can do your overclocking from the Core Center program. I haven't been able to change the multiplier though.
4. You have to download a processor driver from AMD to get your processor to work correctly. Before I installed that processor driver, my processor speed stayed at 2ghz all the time even at idle. With the processer driver installed, it clocks down to 1Ghz during idle and light INternet browsing. But it'll ramp up to 2Ghz when you start doing more.