The PPGA478 and the PGA478 are terms used for a central processing unit socket called "Socket 478" to denote the type of form factor used to manufacture it. Also known as "Socket N," Socket 478 is the product of semiconductor company Intel Corp., released in 2000 to physically and electrically connect processors from its then-flagship Pentium brand and low-end Celeron brand.
General Description
Socket 478 is named after the number of pin holes it has to accommodate the pins of the Intel Pentium or Celeron processor. It is a square-shaped structure that measures 1.38-by-1.38 inches, or 3.5-by-3.5 centimeters. Like other CPU sockets, Socket 478 is used to connect the processor to the motherboard for data transmission, as well as physical support and protection so that it does not get easily damaged.
PGA vs. PPGA
The PGA and PPGA prefixes used for Socket 478 are actually acronyms. PGA stands for "pin grid array," which means that the pin holes are arranged in an orderly, grid-like format on the socket. The pins are arranged in a 26-by-26 formation, with a 14-by-14 section depopulated in the middle. Moreover, Intel blocks out two pin holes. Thus, 26-by-26 minus 14-by-14 minus 2 equals 478 usable pins. Socket 478 is usually made of ceramic; sometimes it is called "CPGA" to denote the type of PGA variant. PPGA stands for another popular PGA variant of Socket 478 -- the plastic pin grid array. This means that the socket is made of plastic.
Other PGA/PPGA478 Specs
Typically, PGA478 and PPGA478 sockets have a flip-chip feature. This means that the hottest part of the processor -- the back of the die, the wafer of semiconductor material that holds the CPU's processing unit or units -- is exposed. This allows users to introduce a heatsink as a cooling mechanism and thus prevents possible malfunction from overheating. Also, a zero insertion force feature is included so that users do not need any force at all to insert or remove the CPU.
Processor Specs
PGA478 and PPGA478 sockets support Intel Pentium 4 chips, the fourth major iteration of the Pentium brand; and Intel Celeron chips with a processing speed range of 1.4GHz to 3.4GHz and 1.7GHz to 2.8GHz, respectively. They also accommodate the high-end yet less energy-efficient counterparts, Celeron D and Intel Pentium 4 Extreme Edition, with a processing speed range of 2.13GHz to 3.2GHz and 3.2GHz to 3.4GHz, respectively. Also, each Socket 478-compatible CPU has a data transfer speed of 400MHz, 533MHz or 800MHz.
Tags: Intel Pentium, means that, denote type, grid array, Pentium brand, PGA478 PPGA478