Source : Free On-Line Dictionary of Computing

x86 processor socket
     
         One of the series of standard sockets
        into which you can plug various {x86} {microprocessors}.
        These vary in the number of pins, package, voltages, bus
        speeds, and supported processors.  {Motherboards} often have
        {clock multipliers} so that the processor runs at a multiple
        of the bus speed.
     
        Socket 1, 169 pin {LIF}/{ZIF} {PGA} (17x17), 5v, 16-33 MHz
        {486 SX}, {486 DX}, {486 DX2}, {DX4 Overdrive}.  Socket 1 was
        the first standard {Intel 486} socket.
     
        Socket 2, 238 pin LIF/ZIF PGA (19x19), 5v, 25-50 MHz 486 SX,
        486 DX, 486 DX2, 486 DX4, DX4 & {Pentium Overdrive}.  Updated
        Socket 1, added support for Pentium Overdrive processors.
     
        Socket 3, 237 pin LIF/ZIF PGA (19x19), 3.3/5v, 25-50 MHz 486
        SX, 486 DX, 486 DX2, 486 DX4, DX4 & Pentium Overdrive.
        Supports 5V & 3.3V processors, considered the latest 486
        socket.
     
        Socket 4, 273 pin LIF/ZIF PGA (21x21), 5v, 60/66 MHz Pentium
        60/66 and Pentium Overdrive, only 5v.
     
        Socket 5, 296 pin LIF/ZIF, 320 pin LIF/ZIF {SPGA} (19x19 or
        37x37), 3.3v, 50/60/66 MHz Pentium 75 - 133MHz, Pentium
        Overdrive, only 3.3v.
     
        Socket 6, 235 pin ZIF PGA (19x19), 3.3v, 25-40MHz.  Unpopular
        advanced Socket 3, rarely seen / paper spec 486 DX4, Pentium
        Overdrive, only 3.3v.
     
        See also {Socket 7}, {Socket 8}, {Super 7}, {Slot 1}, {Slot
        2}, {Slot A}.
     
        {CPU Sockets chart
        (http://users.erols.com/chare/sockets.htm)}.
     
        {CPU Sockets (http://webm3308.ntx.net/cpusockets.htm)}.
     
        (1999-08-05)