^Bit of a misleading reply, Saint.
There's no such thing as FSB on the new Intel systems, as it is now called Base Clock. Also you most certainly can change the CPU ratio, although it's actually called the multiplier. However, it cannot be raised beyond where it is at stock by more than 1. Basically at stock, turbo boost will run the multiplier 1 higher than it shows in BIOS (don't know why, exactly) and up to 4 higher at full turbo.
If the multiplier is manually changed it will disable turbo boost.
But to really get an overclock, you do have to increase the base clock, and like Saint said, it will also cause the RAM speed to change. RAM works similarily with 6x, 8x, and 10x multipliers of the base clock.
A lot of people just set 200 base clock and 18, 19, or 20 CPU multiplier and 8x RAM multiplier (if you have 1600mhz RAM). It can take some voltage tweaking though. Try to get the RAM to run at the rated speeds and timings.