Dorothy Bradbury wrote:

P-M & P4-M are not the same chip.
If your laptop uses P4-M you can't fit a P-M into it.

There was no mention of Pentium M (Dothan can't reach 2.4 GHz yet).

The question was:

What is the difference between "Mobile Pentium 4" and
"Mobile Pentium 4 - M" chips?

Mobile Intel Pentium 4 Processor:
http://intel.com/products/notebook/p...obilepentium4/
http://processorfinder.intel.com/scr...p?ProcFam=1025
http://intel.com/design/mobile/datashts/253028.htm
http://intel.com/design/mobile/datashts/302424.htm

Mobile Intel Pentium 4 Processor - M
http://intel.com/products/notebook/p...rs/pentium4-m/
http://processorfinder.intel.com/scr...sp?ProcFam=826
http://intel.com/design/mobile/datashts/250686.htm

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Regards, Grumble