AMD Opteron 244 - Setting CPU Frequency

[CogTech]

I currently have a dual-cpu system on an Asus K8N-DL and BIOS gives us the option to change the CPU Frequency from 200 (default) up to 400.

If the CPU frequency is 200 and the memory is running at 400MHz, will the CPU act as a bottleneck?

How fast can I overclock the CPU before it gets damaged? How should I set the threshold for the built-in temperature sensor?

Thanks.