Socket 479

Socket 479 has 479 pin holes. Pentium M processors in PGA package have 479 pins that plug into this zero insertion force socket. Only 478 pins are electrically connected (B2 is reserved and "depopulated on the Micro-FCPGA package"). Although mechanically similar, Socket 478 has one pin fewer, making it impossible to use a Pentium M processor in a Socket 478 board. For this reason, some manufacturers like Asus have made drop-in boards (e.g. CT-479) which allow the use of Socket 479 processors in Socket 478 boards. Conversely, it is impossible to use any Socket 478 desktop Celeron and Pentium 4 processors in a Socket 479 board as they are electrically incompatible with Socket 479 despite being mechanically pin-compatible with it. For the same reason, Celeron M and Pentium M processors are pin and electrically incompatible with Pentium III-based Socket 479 boards. The other difference is the 855GM chipset graphics core runs at 200 MHz while the 855GME runs at 250 MHz. In 2006, Intel released the successor to Socket 479 with a revised pinout for its Core processor, called Socket M. Socket M supports a 667 MT/s FSB with the Intel 945PM/945GM chipsets. This socket has the placement of one pin changed from the Pentium M version of Socket 479; Socket M processors will physically fit into a Socket 479, but are electrically incompatible with most versions of Socket 479 (except using ATI north bridge RC415MD). ==Socket and naming confusion==

There exist multiple electrically incompatible, but mechanically compatible processor families that are available in PGA packages using Socket 479 or variants thereof: PBGA479 or H-PBGA479. It should be however pointed out that these designations denote rather the CPU package itself and not the socket, which the BGA variants do not use at all (they are intended to be directly soldered to the mainboard, e.g. in an embedded system). The non-BGA counterparts of these CPUs use any one of the above-mentioned sockets, not just the Socket 479. ==See also==