MikeC wrote:All mobile Pentium M and Celeron M processors are by definition 479 pin processors.

Then why do resellers seem to all list them as 478 pin, as well as the specs on intel's site listing both 478 and 479 pin versions? Seems weakly defined to me.

You cannot use a standard desktop 478 processor into any 479 socket motherboard. You cannot use a mobile 479 processor into any 478 socket motherboard. That wasn't quite the question. I don't want to know about a P4 478 chip, I want to know about a Pentium M 478 chip in a board that has a Pentium M...

I ordered the i915GMm-HFS with a Pentium M 740. I was told by my reseller that a previous buyer had problems POSTing with this combination. Intel support claimed that it was due to the retail Pentium M 740 (BX80536GE1733FJ) being a Socket 478 chip vs. Socket 479. Can those who have built systems us...

If you check Intels web site a little more closely -and specifically, This pdf document (section 4) you will see that the P-M is available with a 478- pin Micro-FC P GA packaging and a 479- ball Micro-FC B GA package. And later that pin B2 is depopulated on the FCPGA variant. BGA (ball grid array) ...