Overclocking / Modding → [OC] Is Temperature and Voltage the only limitation ?

Is Temperature and Voltage the only limitation for overclocking ?

Like if I have a P4 1.8Ghz Northwood. @ 1.5V.
If i get it to 0C would i be able to put it to 18X200Fsb (3.6Ghz) @ say 1.85V ?

There's also the limits of the motherboard, RAM, and how well they facilitate it.

Only recently boards w/ AGP/PCI lock have come to the AMD side, while they were practically all but mandatory to be featured on Intel mobo's. With this, it helps keep devices on there in spec, so that you *shouldn't* have to deal with those that have onboard everything and still get good o/c results

Also, stepping revisions can make a huge difference in terms of how well a CPU can o/c. Just look at how the AGOIA 1600's did. And currently several different steppings of the T-bred B's have yielded good results.

What Motherboard limitations ?
Cooling the chipset ?

Ram is understandable. But i guess if you get DDR 400 and set it to 1:1 it should work.
At 200Fsb won't the AGP be set standard ? 1/2 or 1/3 ?