R51 CPU Upgrade

[rossk7]

Hello all,
Any help on my question will be greatly appreciated. I am trying to upgrade the CPU in my thinkpad. I installed a Celeron M 1600MHz since the research I did, it was the closest to oem on the same FSB(400MHz) but it didn't work. It took the 120Gb HDD and 2Gb Memory upgrades perfectly. Specs are as follows;

IBM Thinkpad R51
2883-2ZU
Celeron M 320
1300MHz, 512Kb

[dr_st]

Which Celeron M was it - 380, 420 or 620?

[rossk7]

Celeron M 320, listed in original post. Ran CPU-Z to get the following

Intel Celeron M 320
Banias Socket 479 mPGA

I am a desktop builder, so this is new to me, isn't socket 479 the same as a mobile socket 478?

[underclocker]

I'm pretty sure the newer Celeron's won't work. They have 1MB cache and Dothan cores. I had a similar problem with a T40, a newer Pentium M cpu (725A) wouldn't work.

IBM probably stopped adding CPU's to the microcode table so the BIOS and EC don't support booting with it.

Best upgrade bets are Banias or Dothan Pentium M cpu's. I know a 725A worked in my R51 - and still works great.

[dr_st]

Sorry, I meant which Celeron M was it that you upgraded to, not from.

[rossk7]

I'm pretty sure it was a Celeron M Banias. not sure what model. The company is sending me a Pentium M 1.7, so I will reply back on whether it works or not...thanks for the assistance