AMD Athlon XP-M 1800+ (25W) socket: Socket 563

What the Athlon XP-M 1800+ (25W) is

The AMD Athlon XP-M 1800+ (25W) is a 1400 MHz low power mobile processor from March 2003. It runs one K7 Barton core at 1400 MHz with no turbo, so 1 core gives 1 thread. Cache is 256 KB of L2 on a 130 nm process. Power is rated at 25 W in a 563-pin microPGA package for thin notebooks. A duplicate cpu_list row repeats the same spec, so one page covers both entries. The Socket 563 page names 25 W as a low-power envelope, which supports the rating.

The 1800+ (25W) gives thin notebooks a low clock option with Barton cache structure cut to 256 KB like Thorton, which keeps power at 25 W with PowerNow control. It uses a 200 MT/s front side bus with a 14x multiplier. AMD aimed the bin at small notebooks where silence matters more than speed. The chip supports MMX, SSE and Enhanced 3DNow.

Low clocks with a 25 W cap suit always-on portable use. The part sips power at idle with SpeedStep trimming voltage, which extends battery life in small bodies. That is why the 1800+ (25W) shipped in thin designs that could not carry 35 W or 55 W Socket A mobiles.

Socket and motherboard compatibility

The 1800+ (25W) fits Socket 563 notebooks with low power Barton BIOS support. It needs a microPGA board with 563 lands. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Thin notebooks are the natural match. Bundled Socket 563 desktop boards also accept the chip where listed. Socket 462 mobiles do not seat in the 563-pin socket.

Memory, PCIe and cooling

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

Front side bus operation at 200 MT/s 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 for 25 W with quiet fans.

Upgrade paths

On Socket 563 the steps are higher Barton 563-pin parts such as the 2000+ (25W) at 1533 MHz where listed. Standard power Socket 462 mobiles offer higher clocks with larger power. A move to Socket S1 needs a new notebook. The chip lifts with the socket mechanism, so swaps need no solder work.