Intel Mobile Pentium 4 2.66 socket: Socket 478

What the Mobile Pentium 4 2.66 is

The Intel Mobile Pentium 4 2.66 is a 2.66 GHz single-core mobile processor from June 2003. It runs one NetBurst Northwood core at 2.66 GHz with no turbo and no Hyper-Threading on this rating, so 1 core gives 1 thread. Cache is 512 KB of L2 on a 130 nm process. Power is rated at 66.1 W in a Socket 478 package. The cpu_list 1/2 threads and 66 W values match the table single thread and 66.1 W after rounding, and the table values are used here.

The 2.66 Mobile P4 uses a 533 MT/s front side bus with a 20x multiplier at 1.20 V to 1.55 V. Intel sold it at 218 dollars in June 2003. The chip supports MMX, SSE and SSE2. Mobile Pentium 4 HT 2.66 parts at the same 2.66 GHz add Hyper-Threading for notebook multitasking, so threads separate the bins at identical frequency.

Single thread with a fast bus suited large notebooks for single-task office use. The 66.1 W envelope needs a desktop-replacement heat pipe with wall power. That is why Mobile P4 parts cost less than HT mobiles at the same clocks despite sharing cache.

Socket and motherboard compatibility

The Mobile 2.66 fits Socket 478 desktop-replacement notebooks with Mobile P4 support. It needs a notebook Socket 478 board. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Large DDR notebooks are the natural match. Maker lists decide fit by threads, since HT mobiles need different BIOS paths.

Memory, PCIe and cooling

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

A 533 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 large notebook heat pipe for 66.1 W operation.

Upgrade paths

On Socket 478 the steps are Mobile Pentium 4 2.80 and 3.06 parts. HT 2.66 mobiles add threads at the same clocks. Pentium M parts on Socket 479 offer thin paths. The 2.66 removes with the socket mechanism, so swaps need no solder work.