Have you checked the workmanship on the L1 traces or are they all connected? Are you running 100 Mhz FSB? (IE 10x100) or some other combo to get 1Ghz? 1 Ghz is not too shabby. What do you expect to be able to get up to? The point being, some of the above issues are valid, but how far you can go, more often than not, depends upon the luck of the draw when your CPU was picked out of inventory and shipped to you. You may be able to get it a little higher with more aggressive cooling. I experimented with my Duron 600 once, by trickling a continuous stream of Freeze Spray on it, it overclocked further with less of a voltage increase. An accepted tenet in electronics is that the cooler a bipolar, or cmos junction is held, the better the performance, especially with respect to frequency.