Intel Pentium 4 HT 2.80 socket: Socket 478

What the Pentium 4 HT 2.80 is

The Intel Pentium 4 HT 2.80 is a 2.8 GHz single-core desktop processor with Hyper-Threading from May 2003. It runs one NetBurst Northwood core at 2.8 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 69.7 W in a Socket 478 package with part numbers SL6WJ and SL6WT. The cpu_list 70 W value matches the table 69.7 W after rounding, and the table value is used here.

The 2.80C uses an 800 MT/s front side bus with a 14x multiplier at 1.475 V to 1.525 V. Intel sold it at 278 dollars in May 2003. The chip supports MMX, SSE and SSE2 with Hyper-Threading. Celeron 2.80 parts at the same 2.8 GHz offer 128 KB without threads on a 400 MT/s bus, so cache, bus and threads separate the lines. Prescott 2.80E parts at the same clocks offer 1 MB of cache on 90 nm as a die shrink alternative with higher power.

Flat power with rising clocks marks late Northwood maturity. The move from 69 W on the 2.60 to 69.7 W on the 2.80 needs no cooler change. That is why the 2.80 became a common office upgrade on boards qualified for slower Northwood HT parts.

Socket and motherboard compatibility

The Pentium 4 HT 2.80 fits Socket 478 desktops with an 800 MT/s bus and Northwood HT support. It needs a 478-pin board. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

DDR office towers are the natural match. Intel 865 boards accept the chip with a 69.7 W cooler.

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 69.7 W heatsink.

Upgrade paths

On Socket 478 the steps are the Pentium 4 HT 3.00 and 3.20 Northwood parts. Prescott 2.80E offers more cache as an alternative. Beyond Socket 478 a move to LGA 775 needs a new board. The 2.80 lifts with the lever, so swaps need no solder work.