C2 c2e & c4 c4e state support- what is it? and is it worth urning on?

hi, i basically just wondered what the actual functions of the c2/c4 state supports are in the bios?

i understand that it saves on cpu power consumption but thats about it and typing it into google only leads me to other forums saying to disable it when overclocking for more stability...

I'm running a e8400 and its not overclocked so i just wondered wether it is worth turning c2/c2e on, and wether to turn c4/c4e state support on aswell or to leave that one disabled?

and what are the benefits or disadvantages it offers?

im running vista x64 and like an occasional game, would the state support interfere with gaming?

thanks rob