Intel Pentium M 725 socket: Socket 479

What the Pentium M 725 is

The Intel Pentium M 725 is a 1.6 GHz single-core mobile processor from June 2004. It runs one P6 variant Dothan core at 1.6 GHz with no turbo, so 1 core gives 1 thread. Cache is 2 MB of L2 on a 90 nm process. Power is rated at 21 W in a Socket 479 package with a 400 MT/s front side bus and a 16x multiplier at 0.988 V to 1.34 V.

The 725 steps above the 1.5 GHz 715 with the same 2 MB cache and 21 W envelope, using one higher multiplier at the same voltage window. Intel sold it at 241 dollars in June 2004. The chip supports MMX, SSE and SSE2 with Enhanced SpeedStep. A 725A shares clocks as an OEM variant from July 2005, so board lists may show either suffix. Banias 1.6 GHz parts with 1 MB offer half the cache at higher power, which is why Dothan replaced Banias in Centrino designs.

Model numbers with 400 MT/s and 533 MT/s buses need care. The 725 at 1.6 GHz uses a 400 MT/s bus with a 16x multiplier, while the 730 at the same 1.6 GHz uses a 533 MT/s bus with a 12x multiplier and 27 W power. That bus split is why the 725 suits 855 chipset notebooks and the 730 suits 915 chipset notebooks, even though clocks match.

Socket and motherboard compatibility

The Pentium M 725 fits Socket 479 thin notebooks with DDR memory, a 400 MT/s bus and Dothan support. It needs a mobile 479-pin board with 400 MT/s chipset paths. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Centrino notebooks with Intel 855 chipsets are the natural match. Boards listing Dothan 400 MT/s parts accept the 725 with a 21 W heat pipe. Socket 478 Mobile Pentium 4 parts need desktop-replacement chassis instead.

Memory, PCIe and cooling

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

A 400 MT/s bus ties the CPU to the mobile chipset, while graphics hangs off the chipset. No PCIe lanes originate on the die. Cooling is the notebook heat pipe for 21 W with quiet fans. SpeedStep extends battery life by cutting clocks on battery power.

Upgrade paths

On Socket 479 the steps are the Pentium M 735 at 1.7 GHz and the 745 at 1.8 GHz with the same cache and power. The 715 at 1.5 GHz offers a slower clock where listed. Beyond Socket 479 a move to Socket M needs a new notebook for Core Solo parts. The 725 removes with the socket mechanism, so swaps need no solder work.