Intel Mobile Pentium 4 HT 2.66 socket: Socket 478

What the Mobile Pentium 4 HT 2.66 is

The Intel Mobile Pentium 4 HT 2.66 is a 2.66 GHz single-core mobile processor with Hyper-Threading from September 2003. It runs one NetBurst Northwood core at 2.66 GHz with no turbo, so 1 core gives 2 threads. 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 66 W and 2.667 GHz values match the table 66.1 W and 2.66 GHz after rounding, and the table values are used here.

The 2.66 HT uses a 533 MT/s front side bus with a 20x multiplier at 1.20 V to 1.55 V. Intel sold it at 234 dollars in September 2003. The chip supports MMX, SSE and SSE2 with Hyper-Threading. Mobile Pentium 4 2.66 parts at the same clocks offer a single thread without Hyper-Threading, so threads separate otherwise identical ratings.

Hyper-Threading with modest mobile power suited large notebooks for multitasking on the road. The second thread hides memory latency during office tasks, which is why the HT 2.66 cost more than the non-HT 2.66 despite sharing cache.

Socket and motherboard compatibility

The Mobile HT 2.66 fits Socket 478 desktop-replacement notebooks with mobile HT support. It needs a notebook Socket 478 board with Hyper-Threading paths. 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.

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 notebook heat pipe for 66.1 W operation.

Upgrade paths

On Socket 478 the mobile HT steps are the 2.80 and 3.06 parts at the same power class. Non-HT 2.66 mobiles offer the same clocks without threads. Pentium M parts on Socket 479 offer thin paths. The 2.66 removes with the socket mechanism, so swaps need no solder work.