P4

P4 may refer to:

Computing

• Intel Pentium 4, a 7th generation processor design
  • The "P4 power connector" introduced to power it and later CPUs in the ATX12V 1.0 standard
• The i486DX (P4) model of the Intel 80486, a high-performance microprocessor
• P4 (programming language), for describing packet forwarding

Hobbies

• Protofour, or P4, a set of standards for model railways

Media

• P4 Radio Hele Norge (PFI), a Norwegian radio company
  • Kanal 24 (Kanal 4), which acquired the Norwegian P4 channel from PFI
• Persona 4, a 2008 video game

Military

• Skaraborg Regiment (armoured), a Swedish army unit whose designation is P 4
• Peugeot P4, a 4-wheel-drive unarmoured light vehicle used by the Military of France

Science

• Biosafety level 4, microbiology laboratory safety procedures to handle level-4 pathogens
• Tetraphosphorus (P₄), an allotrope of phosphorus
• Group p4, the plane symmetry group Wallpaper group p4
• Progesterone (Pregn-4-ene-3,20-dione), a steroid hormone
• Kerberos, the fourth moon of Pluto, discovered in 2011
• Perfect fourth, an interval in music theory
• Enterobacteria phage P4, a bacteriophage
• P4: an EEG electrode site according to the 10-20 system
• P4 cell, a stage in the Caenorhabditis elegans embryonic development

Roads

• P4 road (Latvia), a first class State road connecting Riga and Ērgļi
• P04 road (Ukraine), a state regional road connecting Kiev and Zvenyhorodka

Other uses

• Papyrus 4, a New Testament manuscript
• Trans-Pacific Strategic Economic Partnership, or P4, a free trade agreement between Brunei, Chile, New Zealand, and Singapore

See also

• 4P (disambiguation).
• Phosphate, molecular formula PO₄^3−.