P4: How's it different?
Will it fit into my socket 370 mobo?
Please don't try fitting a P4 to your existing mobo. You'll need an entirely new one and for the time being you'll have to make it an Intel Garibaldi D850GB, 'cos it's the only one there is.
And you'll need to upgrade your power supply too. Willamette/P4 needs an ATX 12V supply that has an additional 12 volt supply that plugs into the mobo right next to the CPU socket. The 0.13 micron die shrink of P4 coming later next year will have additional pins on the processor, almost all of them providing extra volts and amps, so this additional header may disappear in the long term.
The case you put all this in can, however, be that battered old ATX one with the coffee stains you're currently using. Intel's demo systems come in very slinky Cooler Master cases with two additional fans on the top and back to augment the ones on the processor and power supply.
If our experience is anything to go by, these merely add noise and create an annoying cold draught. The processor in our system never became even warm to the touch, even when running at 100 per cent processor utilisation for four days without a break. The hard disk runs hotter. ®