I have a northwood 478 so we're on the same page as far as that goes.
Mines a 533FSB also. I meant my current cpu chip is running at 533fsb.
Here's what I pulled off the asus site. The specs part of their server is down so I didn't get much.
World's first 3GHz+ CPU and Intel Hyper-Threading Technology support!!
P4PE (Intel 845PE) Series
ASUS P4PE is based on Intel® 845PE which supports 533MHz FSB, 3GHz+ CPU, Intel Hyper-Threading technology, CrashFree BIOS, C.P.R. (CPU Parameter Recall), 3 DIMM for PC2700/PC2100 memory
Loosely translated it means this. Your motherboard will only go 533 on the front buss because it was not built to go at any other speed. It will accept only a 533FSB cpu chip. It's not designed to go any other speed most likely to keep the cost of making the MOBO down or to force you to buy another board to go faster. I think the latter applies here.
Cpu chips will only go one speed unless you over clock them. This is why you have to pay such close attention when you buy a cpu chip from Intel dealers. The cpu will go one speed and that speed is stated on the specs for the cpu chip. That is why I beat you guys up with> Do your homework before you buy anything. COMPATIABLITY is the name of the game.
So bottom line is if ya wanna go faster, Match the motherboard and the cpu chip TOGETHER. DON'T go cramming in to the socket what is not meant to be there. You won't like what happens next, trust me. Been there...