Intel Pentium 4 HT 2.40 socket: Socket 478

What the Pentium 4 HT 2.40 is

The Intel Pentium 4 HT 2.40 is a 2.4 GHz single-core desktop processor with Hyper-Threading from May 2003. It runs one NetBurst Northwood core at 2.4 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 66.2 W in a Socket 478 package with part numbers SL6WR and SL6WF. The cpu_list 66 W value matches the table 66.2 W after rounding, and the table value is used here.

The 2.40C opens the Northwood HT C line with an 800 MT/s front side bus and a 12x multiplier at 1.475 V to 1.525 V. Intel sold it at 178 dollars in May 2003 as the entry Hyper-Threading desktop. The chip supports MMX, SSE and SSE2 with Hyper-Threading. Non-HT Northwood 2.40B parts at the same 2.4 GHz offer 512 KB without threads on a 533 MT/s bus, so bus and threads separate the bins at identical frequency.

Entry Hyper-Threading with modest power suited office multitasking towers. The 66.2 W envelope needs only a standard Socket 478 cooler with normal airflow. That is why the 2.40C became a common corporate desktop chip with DDR memory.

Socket and motherboard compatibility

The Pentium 4 HT 2.40 fits Socket 478 desktops with DDR memory, an 800 MT/s bus and Northwood HT support. It needs a 478-pin board with Hyper-Threading paths. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Corporate DDR towers are the natural match. Intel 865 boards accept the chip with a 66.2 W cooler. Older 533 MT/s boards need a chipset check for 800 MT/s operation.

Memory, PCIe and cooling

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

An 800 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 66.2 W heatsink.

Upgrade paths

On Socket 478 the steps are the Pentium 4 HT 2.60 and 2.80 Northwood parts with the same cache. Non-HT 2.40B parts offer the same clocks without threads. Beyond Socket 478 a move to LGA 775 needs a new board. The 2.40 lifts with the lever, so swaps need no solder work.