Does Powerstrip recognize your S3 graphics?
If so, open the utility in your task bar, it should be under performance settings (or something of the sort) after opening it, there should be two sliders to the left, one is your core speed and the other is your memory speed.When you start to overclock, move the slider only about 3-5 MHz on both sliders.After that, minimize the utility in your task bar again and start up a demanding 3d game, one that your card can support but you can't crank up the settings, and start playing, If you notice any rendering errors in the background or foreground, clock back down, if you notice no change, continue increasing the core and memory speeds by 3-5 MHz each while testing in between sesions.DO NOT SKIP TESTING WITH A GAME, OR IGNORE ANY KIND OF RENDERING ERROR!
On overclock-friendly cards you can go well above 80-100 MHz past the standard speeds!
Remember, don't increase the slider by more than 5 MHz at a time, doing so can cause the card to go into what I call SHOCK, after applying the changes the screen will flicker, an indication that you have gone too far in one session, like I said before, doing this voids your waranty and may cause permanent damage to your card.Just follow my directions and you'll be fine!
GOOD LUCK....