can a pentium M operate in a pentium 4 (mobile) system

[kxb0016]

i have a pentium 4 M system (thinkpad A31) iam wondering if it can run a pentium M. the cpu's are very simular in specs the difference is that the pentium M has a two to four times greater cashe. my concern is that the motherboard with not accept the new cpu.

please direct me to some information that will help

thanks

[kxb0016]

i have a A31 and the T40 thinkpad uses the pentium M

most of the spec are similar - can so one conclude if it is or not possiable.

[soeren]

no...the Pentium M has the socket 479 and the P4m socket 478......one pin to much