Hardware components of the PC
The System Board
Processor Sockets

Over the years, and more recently, there has been several different types of socket used to house the processor on the motherboard. The main reason for this is that each new processor has had more pins, the latest Pentium 4 uses a 423 pin, socket 423 interface, but future Pentium 4 will have an extra 55 pins will use an mPGA478 interface

One of the most popular processor sockets on the motherboard is the Socket 7 shown below.

 

Socket 4 Socket 5 Socket 7 Socket 8

The sockets above are called Zero Insertion Force (ZIF) sockets, they have a lever on the left hand side, which, when raised, allows the processor to be dropped into the pin sockets. Once the processor has been fitted the lever can be closed trapping the pins in the socket and making the connections. A socket similar to this, called a Low Insertion Force (LIF) socket, has been used that do not have a lever, and require a small amount of pressure on the processor to make a secure connection. Variations of the type of socket shown above have been used, generally they have got larger in order to accommodate the increasing number of pins, such as the socket 370 and 430.

There are difference in the sockets, even though they may look alike, for example the socket 5 and 7 look alike but the socket 7 requires 5.0 amps at 3.3 volts, whereas the socket 5 only requires 4.33 amps. Some versions of the socket 7 have pin 321 missing in order to provide a key.

The Pentium II and some Pentium III processors used the Slot I (shown in the photograph in the section on typical motherboard hardware characteristics).

Socket 7 can be used for all the predecessors of the Socket 5 and was used for AMD K6-2, Socket 370 was used for the VIA processors and the Socket A for the AMD Athlon and Duron.

  • With all these different types of socket and processors the IT System Support Technician must ensure that the socket is correct and they set up any switches on the motherboard correctly.
  • Take care not to bend any pins whilst fitting the processor.