Max CPU upgrade for Toshiba Satellite 1115-s103

This is one of those Compal built Toshibas where you have to completely disassemble it to replace drives, etc. It is torn down on my bench waiting for a hard drive so I thought maybe to upgrade the CPU to max allowable.

As bought it is a 1.5gHz/256L2 Mobile Celeron 478 pin 400 fsb Northwood BIOS v1.2

The latest BIOS v1.5 states:

Version 1.50 Â Â Â 11-20-2003

* Added support for "C1" step CPU of Pentium 4m 1.8 GHz
* Added support for "D1" step CPU of Intel Celeron 1.5, 1.6, 1.7, 1.8, 1.9, 2.0 GHz and Pentium 4M 1.8.GHz.

From what I have read, with the netburst architecture, the P4M 1.8 is the pick of the litter.

However, my question is,

Would a P4M 2.0 work?

This would be identical to the P4M 1.8 except for a 2.0 gHz multiplier, a multiplier already established for the Celeron choices.

I guess the question is how does the BIOS communicate with the cpu for identification? If it translates stepping codes, then the P4M 2.0 probably won't work. However if it merely detects the multiplier, then it might.

However, the former is suggested when they specifically state support for particular stepping codes.

Any ideas?

Thanks in advance,
Regards,
Tom

PS. Some comment on dissipation. All the v1.5 CPUs are 30w except for the 2.0 Celeron which is 32w. The 1.8 P4M is 30w and the 2.0 P4M is 32w so in that case, the cooler and psu should be able to handle it.

I suspect that the BIOS may work off stepping codes so that higher dissipation CPU's are disallowed since they would be a big problem if used.