Intel Pentium 4 2.66 socket: Socket 478

What the Pentium 4 2.66 is

The Intel Pentium 4 2.66 is a 2.66 GHz single-core desktop processor from August 2002. It runs one NetBurst Northwood core at 2.66 GHz with 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 110 W value differs from the table 66.1 W, and the table value is used here.

The 2.66 uses a 533 MT/s front side bus with a 20x multiplier. Intel sold it at 401 dollars in August 2002. The chip supports MMX, SSE and SSE2. Mobile Pentium 4 2.66 parts at the same 2.66 GHz share clocks with notebook power tables, so board type separates desktop from mobile at identical frequency.

Mainstream balance with a fast bus made the 2.66 a common DDR tower chip. The 66.1 W envelope needs only a standard Socket 478 cooler. That is why the 2.66 cost the same as the 2.60 despite a faster bus, with chipset support deciding the pick.

Socket and motherboard compatibility

The Pentium 4 2.66 fits Socket 478 desktops with a 533 MT/s bus and Northwood support. It needs a 478-pin board. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

DDR towers are the natural match. Intel 845PE boards accept the chip with a 66.1 W cooler.

Memory, PCIe and cooling

Memory is DDR through the board chipset. The board sets speed and capacity.

A 533 MT/s bus ties the CPU to the chipset, while AGP handles graphics. No PCIe lanes originate on the die. Cooling uses the Socket 478 bracket with a 66.1 W heatsink.

Upgrade paths

On Socket 478 the steps are Pentium 4 2.80 and 2.66 HT parts. Celeron 2.60 offers value with less cache. Beyond Socket 478 a move to LGA 775 needs a new board. The 2.66 lifts with the lever, so swaps need no solder work.