Intel Pentium 4-M 2.50 socket: Socket 478

What the Pentium 4-M 2.50 is

The Intel Pentium 4-M 2.50 is a 2.5 GHz single-core mobile processor from April 2003. It runs one NetBurst Northwood core at 2.5 GHz with no turbo, so 1 core gives 1 thread. Cache is 512 KB of L2 on a 130 nm process. The package is Socket 478 for notebooks. This page omits a TDP rating because no opened source states power for the 2.50 P4-M bin.

The 2.50 P4-M uses a 400 MT/s front side bus with a 25x multiplier and SpeedStep control. Intel sold it in April 2003 as a mainstream notebook step above the 2.40. The chip supports MMX, SSE and SSE2. Mobile Pentium 4 2.50? No desktop-replacement 2.50 exists at the same clocks, so the P4-M stands alone with SpeedStep savings.

Mainstream notebook balance with a 25x multiplier suited office road use. SpeedStep cuts clocks on battery, which matters more than peak frequency in thin bodies. That is why P4-M parts remained popular after Mobile P4 desktop-replacement parts took wall powered niches.

Socket and motherboard compatibility

The Pentium 4-M 2.50 fits Socket 478 notebooks with P4-M support. It needs a notebook Socket 478 board. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Mainstream notebooks are the natural match. Maker lists decide fit.

Memory, PCIe and cooling

Memory is DDR through the board chipset with notebook slots. The CPU has no controller.

A 400 MT/s bus ties the CPU to the chipset, while graphics hangs off the chipset. No PCIe lanes originate on the die. Cooling is the notebook heat pipe with SpeedStep control.

Upgrade paths

On Socket 478 the steps are P4-M 2.60 parts where listed. Pentium M Dothan parts on Socket 479 offer lower power paths. The 2.50 removes with the socket mechanism, so swaps need no solder work.