Re: **LCD Monitor Overdrive Feature??
DDC/CI, or, Display Data Channel/Command Interface allows you to change monitor settings through your o/s, or that's what I've gathered through a few quick google searches. I would leave it off, because after I've messed with my monitor, I usually never touch the controls for it again for a loooong while.
As for overdrive, your monitor didn't come with a manual? I'd check out ASUS' website, wait, ASUS make monitors now?!?!