R40, Celeron - P4-m CPU swap, any other S478 CPUs supported?

[mmmkay]

First post! Hello everyone. Just picked up a refurbished R40 to finally replace my broken iBook G4 1.2 12" (logic board failure after 13mos :@ ! )

It's a 2682-NU2 which comes with the Celeron 1.8 Mobile and 512mb memory. It's pretty fast, though battery only lasts 15 minutes. CDI (the company that does the refurb) is sending me a new battery for it, and I'm going to see if I can snag an Ultrabay battery for it off eBay too. Not bad for $225CDN eh? Then I can swap over that 80GB and memory from the iBook too.. woo hoo.

I've been itching to swap out the CPU for it, to something faster. Preferably a Pentium 4-m since they will scale down to 1.2GHz on battery which should help battery life somewhat. Probably nowhere near the 5:30 that I get on the iBook.. but good enough for school.

Wikipedia has a small list of Pentium 4-m cpus (here)with the highest at 2.6GHz so I guess that would be the fastest processor that I can put in. I think that someone else on the forum reported success with the SL6WZ but since the socket is S478.. does the BIOS recognize any other processors other than Mobile Celerons and P4-m's

[underclocker]

CPU pin-out signals differ with differenct CPU's, voltages differ and your BIOS and Embedded Controller would need to support it.

Not going to happen.

However, 2.4 or 2.6 P4-M's are rather fast.

[Terrahawk]

I wonder if you could put in a desktop Pentium 4 processor. I had a Compaq Evo N1020v that came with a desktop Pentium 4 processor, along with its large power draw. I changed it to a mobile P4, and all I had to do was change two DIP switches.

From that, I guess the pinouts are largely the same, or even identical, but I wonder what else you'd need to do to support a desktop P4 in a laptop.

Even if you could... why would you want to? Heat and battery life would be terrible.

In any case, I don't think you can put anything apart from mobile P4 and celeron in your R40. I had a quick look at the Pentium M pinout (because they use the same bus as the P4) but the pinouts are vastly different, and it uses a 479 pin socket. From what I saw if you somehow managed to put a P-M into a P4 socket, or a P4 into a P-M socket, instant chip destruction and smoke release would be a sure result.

[wolfman]

The P4-M 2.6 is a significant price premium over the P4-M 2.4. I'd just go with the 2.4 and am considering it myself when my R40 runs out of warranty (if I don't extend it).

[mmmkay]

Just picked up a 2.0 P4-m for $5. So when it gets here.. time for a little swap!

Finally pulled that 80gb disk out of the iBook, took all night and about 100 little screws and required pulling off the upper and lower covers just to get at it :@

Now I forgot to unhide the recovery partition before I removed the drive so now I can't read it on my desktop :@

Oh well.. time for some more hacking away at this..

[underclocker]

Just picked up a 2.0 P4-m for $5.

Great price, if there are more, I'd take one for my A31 1.6GHz.

Good luck with the swap.

[mmmkay]

Hey I didn't realize you had to update the firmware of the DVD-ROM/CD-RW in order to read +R discs.. I went through two discs before I figured out that it was the drive not reading them :p

Luckily IBM posted a 24MB ISO that you can download to update the drive's firmware easily.

Edit: Intel does have S478 Pentium M chips but they are not electrically compatible.. just thought I'd clarify that. I was just wondering if any of the other chips would work, like ones with a 533mhz FSB, at a lower speed. However, looking at the big chart of processors, only the 2.6GHz SL6WZ has the lowest TDP out of them all. So looks like if I can get my hands on a 2.4 or 2.6.. looks like the way to go. Along with a new battery + ultrabay battery this should hopefully last at least 4 to 5 hours