Memory Speeds in BIOS.

Hello,

If I set my memory speed to 83% in the BIOS will it be okay?
I want to run 218+FSB and my memory won't have it, if I run it at 83% which is around 204mhz is that okay, or am I about to do something very dangerous and stupid?

Thanks.

WTF... Double post, hopefully a mod will delete the other one.