P4

P4 commonly refers to the Intel Pentium 4, a line of x86-compatible microprocessors introduced by Intel in 2000. The Pentium 4 was built around the NetBurst microarchitecture and targeted desktop performance with higher clock speeds and feature improvements across its evolution. Over several years it moved through different process technologies and socket types, adding enhancements such as larger caches and multimedia instruction sets. The Pentium 4 branding was gradually superseded by newer Intel architectures, notably the Core series, as the company shifted focus to more energy-efficient designs.

P4 also denotes the Programming Protocol-Independent Packet Processors language, a high-level language for programming network data planes. P4 enables users to specify how packets are parsed, matched, and acted upon by programmable network devices. Emphasizing protocol independence and portability, P4 programs can be compiled to run on a variety of targets, including switches, network interface cards, and software switches. The language has been adopted in both research and industry to prototype and deploy flexible, programmable networking functions.

Other uses of the term P4 exist across different domains, often as a model number, project code, or designation within technical literature. Because P4 can refer to distinct concepts, the intended meaning typically depends on the surrounding context, such as hardware, networking software, or a specific product line. When encountering the term, clarifying the domain helps determine which interpretation is intended.