Israfel

Alright, so i have a few questions for the good people of these forums involving Overclocking; a process that i have heard only a little about.

Now my main question is this. i have a GeForce 9400GT GPU, and its only supposed to have like 1 Gig of DDR2 Ram on there, but my PC reads it as 2.2 Gigs (Dunno where the .2 came from.) Is this a Bug, or a result of Overclocking? Now, i don't know what it is, so i never clocked it, so did it come Preoverclocked, or what is it? And if it ISN'T overclocking what are the Pro's and Con's of doing so?