Intel Mobile Pentium 4

The specs are within any ordinary board and at first sight it should fit, however, it's better if you are adviced by someone that knows it for sure, best of all if you contact a motherboard's assistance service.
On the other hand, desktop motherboards with mobile chipsets are the best option (they will use speedstep and make it run much cooler) but they are priced $160 and above.

Seems more or less like any other Prescott A if you ask me. It should work in a socket 478 motherboard that supports Prescotts, which you'll have to look closely at. Most Prescotts are LGA 775- only a few of the very first Prescotts were socket 478, so most 478 boards only support the 478 Northwoods.

Can you be certain the CPU itself is not damaged ?
There should still be many people with older socket-478 based P4s.
Some of your friends likely do, try it in their PCs first.
It would be a shame to buy an antiquated s478 board now, only to see your CPU not work.

I've been wanting to do the same thing with a 3.4GHz chip from a toshiba (broken mobo too - anyone wanting to buy a charger / battery ... from a toshiba P20?).

Check with intel (http://www.intel.com/support/motherboards/desktop/) for compatiblity since a bios flash will be needed. I have an even older mPGA 478 (intel D845WN) which has an old bios update allowing greater than 2.4GHz processors so I don't know that it would take a 3+ GHz processor. Actually since my board uses SDRAM, processors designed for DDR probably can't handle it due to lack of an SD controller.

Jo

But intel's RAM controller is still outside the CPU, on the northbridge, so the only problem should be lower bandwidth and if that is (SHOULD BE) a Northwood only mombo it supplies a higher Vcore than Prescott is rated (1.525V against Prescotts 1.400).

I'm not 100% positive the CPU is working but the MOBO broke at the power cord solder joint. It sparked once at the joint- Would this kill the cpu? There are no noticeable scorches, damage.

JMecc has one of the infamous 845 SDRAM chipsets in his board. The 845 SDRAM chipset was actually the second Pentium 4 chipset, the first being the 850E RDRAM unit. Since the Williamette P4 + expensive RDRAM didn't sell well, Intel decided to have their new 845 chipset (which was supposedly going to only use DDR RAM) use cheap PC100/133 that the Pentium III used as a stopgap measure. Intel shortly found out that the original Socket 423 for the Williamette had electrical troubles and thus designed Socket 478. Later Williamettes used socket 478, and the 845 DDR chipset came out then too. Some motherboard makers probably put the old 845 SDRAM chipset together with socket 478 sockets a la the DDR 400 Core 2 motherboards. This is likely what JMecc has. Most socket 478 boards are the DDR 266 845 unit (400 FSB), DDR 333 855 units (533 FSB), or DDR 400 865/875 chipsets (800 FSB.)

You're 100% right in the fact that on an Intel CPU, the memory controller is off-die on the chipset and the CPU neither knows nor cares what kind of RAM is behind the chipset. The board can actually supply a wide range of voltages to the socket- the only thing that the board would need behind a chipset that can negotiate the right FSB speed is a BIOS flash that has the correct CPUID/voltage tables. So if your motherboard is a 865 or 875 unit, it can support a socket 478 Prescott if it has the correct BIOS flash. Other chipsets cannot support the FSB of the Prescott and thus can't run it.

Not all true. Some variants of the i845 will indeed support Prescott cpus, in the form of Celeron Ds and 533 bus Prescott P4s. However, an updated BIOS is a certainty, so it is usually down to the manufacturer whether or not an i845 mobo will support prescott.

As for this person's mobile P4, I am not well versed on Prescott Mobile P4s, but I do know that Northwood P4s, when placed inside a regular desktop motherboard, would routinely default to 1.2 GHz, 400mhz fsb (because of their bottom-unlocked multiplier they defaulted to the lowest multiplier, 12x). Only motherboards that support multiplier adjustment on p4s (few and far between) would allow you to up the multiplier to the original setting. Most folks just doubled the fsb to achieve a 2.4GHz non Hyperthreading 800fsb Northwood (essentially a 2.4C lacking hyperthreading). Since the CPU in question is a Prescott and run on the 533fsb, I don't actually know what it will default to when fired up in a desktop motherboard.

My 865PE chipset-based board supports essentially all socket 478 processors, I would assume others would, too. It's a Gigabyte, I'd have to look at the model. Nabbed it off ebay for around $40, decent OC options for the time it was from.

If you could reply with the model # i would appreciate it.

Thanks