The Intel Pentium 4 HT 640 was a desktop processor with 1 core, launched in February 2005. It is part of the Pentium 4 HT lineup, using the Prescott architecture with Socket 775. Thanks to Intel Hyper-Threading the core-count is effectively doubled, to 2 threads. Pentium 4 HT 640 has 2 MB of L2 cache and operates at 3.2 GHz. Intel is building the Pentium 4 HT 640 on a 90 nm production process using 169 million transistors. The multiplier is locked on Pentium 4 HT 640, which limits its overclocking capabilities.
With a TDP of 84 W, the Pentium 4 HT 640 consumes a good deal of power, so decent cooling is needed. Intel's processor supports DDR1, DDR2 and DDR3 memory with a dual-channel interface. For communication with other components in the machine, Pentium 4 HT 640 uses a PCI-Express Gen 2 connection. Although the processor doesn't come with integrated graphics, certain motherboards with compatible chipsets can provide this capability.
The SSE4 instruction set is not supported, which can cause problems with modern games, as they require that capability.