Chapter 4: Motherboards^83
Pentium Pro and Pentium II processors, which have unique motherboard
configurations and aren’t typically compatible with other Pentium-based
motherboards. Check your motherboard’s documentation or check with your
PC’s manufacturer to be sure of your choices. Sockets and slots Most upgrade and third-party motherboards have at least
one ZIF (zero insertion force) socket. The most common socket style on newer
computers is the Socket 7 mounting, although processors in the SEC (Single-Edge
Connector) packaging have either a Slot 1 or Slot 2 type processor connection.
The specifications for the CPU you wish to move up to should specify its socket
or slot requirements. Trust me, you won’t confuse a socket for a slot mounting.
See Chapter 3 for more information on processors and their mountings.
Bus speed The bus speed supported on a motherboard must be matched to
the processor. There is usually a direct relationship between the processor
speed and the motherboard speed. In addition to the processor, most of the
other motherboard components, and especially the cache memory, must also
be matched to the maximum allowable motherboard speed.
Cache memory While virtually all Pentium motherboards have between 256K
to 512K of Level 2 cache memory on the board, most Pentium Pro and higher
processors also include Level 2 cache on the chip. Additional Level 2 cache can
be added to the motherboard to improve performance. In fact, on Pentium II
processors and above, most motherboards already have this cache. If you wish
to add cache to your motherboard, remember that it must be matched to the
motherboard’s bus speed.
Memory modules All Pentium and higher motherboards use either the 72-pin
SIMM (Single Inline Memory Module) or the 168-pin DIMM (Dual Inline
Memory Module). DIMMs can be installed individually, but, because of
the 64-bit buses on these motherboards, 72-pin SIMMs must be installed in
matched pairs. Before you start cramming memory modules into open slots,
verify the total amount of memory supported by your motherboard and the
type of memory supported by the processor and chipset.
Expansion bus Consider your current expansion cards and what controllers
or adapters may be built into your new motherboard. You will need to match
your expansion card needs to the number of bus slots available on the mother-
board. If your new motherboard has only one PCI slot and you need three,
there is no retrofit to hel pyou. Here’s a ti pon ex pansion slots on generic
motherboards: make sure that none of the expansion slots, when occupied,
block access to a memory socket, the ROM BIOS, the password-clear jumper,
or the CMOS battery. This can be a hassle later for maintenance or repair.