overclocking

[tacosareveryyummy]

I entered my bios to try to oc my pcpu for the first time. I have an MSI ms7191 motherboard. In the bios the only oc options I have are under one menu. It has a selection for cool'n'quiet (I know what this is), DDR memory frequency (I know what this is also), Ratio change (FID/VID), and Spread Spectrum. What exactly does the ratio change (FID/VID) do and what does spread spectrum do? I am thinking that my mobo does not support oc. Any help would be appreciated. I might just be stuck at stock speeds.