I had the P4PE/L with 2.4B and ran it@3ghz with 2x512mb 3200DDR and it was a nice setup. You can definitely run it with 333DDR by running it asynch to the FSB speed, but the P4 thrives on bandwidth so faster ram would do more for your overall performance, especially since that's a single channel board. To overclock, it's as easy as increasing the FSB speed and picking a memory speed out of the list it'll provide at that FSB that keeps your ram closest to it's rated speed, or speed it can handle. If it isn't stable raise the CPU and ram voltage but don't go past 1.7v actual CPU voltage or you start risking short term damage to the chip.