PC Hardware in a Nutshell, 3rd Edition

Installing a Processor

The following sections describe the steps required to install and configure standard slotted and socketed processors. The steps we describe are generally applicable to any modern processor of a given type, but the details may vary slightly between different processors, particularly with regard to such things as configuring the motherboard and installing heatsink/fan units. If this is the first time you’ve installed a processor, or if you are in doubt about any step, refer to the documentation provided by the manufacturer of your specific processor and motherboard.

Before you install any processor, make sure that you have identified exactly both the processor itself and the motherboard you plan to install it in. If the processor is not new, you can identify it using the steps described earlier in this chapter. All high-quality motherboards have information printed on the board itself that identifies the manufacturer, model, and revision number. If the board does not contain such information, you may be able to identify the board by writing down the full BIOS string displayed by the BIOS boot screen and checking that string against one of the BIOS sites listed in Chapter 3. However, such “anonymous” boards are generally of very low quality, so it’s usually better to replace such a board rather than attempt to use it.

Warning

Before you install a processor, make absolutely sure the processor is compatible with the motherboard. It is not safe to assume merely because the processor fits the socket or slot that that processor will function properly in that motherboard. In some cases, the processor simply will not work. For example, there are many incompatibilities between Socket 370 processors and motherboards. Not all Socket 370 processors can be used in all Socket 370 motherboards, even if the processor and the motherboard were both made by Intel. In that situation, no damage is done. The processor simply doesn’t work.

There are, however, two common situations in which installing an incorrect processor may damage the processor and/or the motherboard:

• Installing a fast processor in a motherboard designed to use only slower versions of that processor. For example, a Slot 1 Pentium II/III motherboard may be rated to accept processors no faster than 450 MHz. Installing a 550 MHz Slot 1 Pentium III may damage the processor or motherboard because the faster processor draws more current than the VRM on the motherboard is designed to supply.

• Installing a processor that requires low voltage in a motherboard that can supply only higher voltage. This problem arises only with Socket 7 and earlier motherboards. Slot 1 and later motherboards and processors automatically negotiate the proper voltage. If the motherboard cannot supply the voltage required by the processor, it simply does not power the processor at all. But if you are installing a late-model Socket 7 processor in an older motherboard, be very certain that that motherboard can supply the proper lower voltages required by the new processor (and that it is configured to do so). Otherwise, your new processor may literally go up in smoke the first time you apply power.

The exact sequence of steps required to install a processor depends on its packaging (slotted versus socketed) and whether it comes with a heatsink and fan installed. Regardless of processor type, always begin by laying the motherboard flat on a firm surface, padding it with the antistatic foam or bag supplied with it. Inserting the CPU (and memory) may require substantial force, so it’s important to ensure that the motherboard is fully supported to avoid cracking it.

Before you install any processor, obtain and read the installation documentation for both the processor and the motherboard. Spending a few minutes doing that may well save you hours of frustration.