Intel Pentium 4 2.0 socket: Socket 478

What the Pentium 4 2.0 is

The Intel Pentium 4 2.0 is a 2 GHz single-core desktop processor from January 2002. It runs one NetBurst Northwood core at 2 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 52.4 W in a Socket 478 package with part numbers SL5YR and SL5ZT on a 400 MT/s front side bus with a 20x multiplier at 1.36 V to 1.435 V. The cpu_list 92 W value differs sharply from the table 52.4 W, and the table value is used here.

The 2.0A carries the A suffix for Northwood 400 MT/s parts, separating it from Willamette 2.0 parts at 75.3 W on 180 nm with 256 KB. The die shrink from 217 square mm Willamette to 131 square mm Northwood with doubled cache cuts power while lifting performance at the same 2 GHz clocks. Intel sold the 2.0A at 364 dollars in January 2002. The chip supports MMX, SSE and SSE2.

Low power with a large cache made the 2.0A a cool office tower chip. The 52.4 W envelope needs only a small Socket 478 cooler with normal airflow. That is why the 2.0A replaced Willamette 2.0 parts in corporate desktops without new chassis designs.

Socket and motherboard compatibility

The Pentium 4 2.0 Northwood fits Socket 478 desktops with DDR memory, a 400 MT/s bus and Northwood BIOS support. It needs a 478-pin board with 400 MT/s chipset paths. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Corporate DDR towers are the natural match. Intel 845 boards accept the chip with a 52.4 W cooler. Willamette-only boards may need a BIOS update for Northwood microcode.

Memory, PCIe and cooling

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

A 400 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 52.4 W heatsink.

Upgrade paths

On Socket 478 the steps are Pentium 4 2.20 and 2.40 Northwood parts with the same cache. Celeron 2.0 parts offer the same clocks with 128 KB as a value alternative. Beyond Socket 478 a move to LGA 775 needs a new board. The 2.0 lifts with the lever, so swaps need no solder work.