If your old PC isn't quite as fast or as powerful as your friends' computers and you'd really like to move up, you have two choices: buy a whole new computer or upgrade the motherboard (and possibly some of your PC's peripheral devices). Depending on the upgrade you do, in general, upgrading your motherboard and CPU will cost you a whole lot less than a brand new computer. The cost may not be the deciding factor though; you may just want to upgrade for the fun and satisfaction of doing it.
Here is a list of the critera you should consider when evaluating your PC and deciding how to upgrade it:
The CPU Which CPU you use with your current motherboard depends mostly on the motherboard itself. While nearly all motherboards can be upgraded with a new processor and chipset, exactly which CPU and chipset is totally dependent on the configuration of the motherboard. If you have a Pentium 75 MHz processor and wish to move up to a Pentium III Xeon, you can count on replacing the motherboard and CPU and perhaps the power supply and more. However, if you merely want to step up to the next level of processor, as long as the processor you wish to move to is within the specification of the motherboard, the move should be fairly effortless.
There are some processors, such as the
Pentium Pro and Pentium IT 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 memoryWhile 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 11 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 motherboard. If your new motherboard has only one PCI slot and you need three, there is no retrofit to help you. Here's a tip on expansion 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.
BIOS The motherboard should use an industry standard BIOS such as those from AMI, Phoenix, or Award. Preferably, the BIOS chip should be the flash , ROM (EEPROM) type. If you have the choice, choose a BIOS that supports Plug and Play (PnP), Enhanced IDE, and Fast ATA. A BIOS that supports the newer power management standards, such as APM and SMM, is a good choice.
Chipset There are reasons to upgrade the chipset on a PC (see Chapter 5), but the rule of thumb is that the chipset must be matched to the processor and the motherboard. The chipset enables and supports such motherboard functions as ECC memory and parity checking, USB ports, multiple CPUs, and other performance issues.
Form factor If you aren't changing your case, then you are stuck with the motherboard form factor that will fit it. Typically, you are looking at an ATX or NLX case and motherboard, unless your system is older, in which case (no pun intended), it is likely a Baby AT. As discussed earlier in this chapter, many of the different form factors share mounting placements, so you can upgrade to any form factor that fits your case. Remember that the power supply is also a component of the form factor and you may want to consider upgrading it as well. If you go that far, consider replacing the case as well.
Built in controllers and interfaces There are those who prefer that the motherboard have as many built in controllers and plugs as possible, and there are those who dislike the "all in one" nature of these boards. If one of the built in controllers fails, which rarely happens, the entire motherboard must be replaced. This can be much more costly than replacing a single expansion card. On the other hand, there is no worry about compatibility among the integrated controllers and interfaces on a motherboard featuring this design.
Documentation This is an excellent consideration when choosing a motherboard. All things equal, the motherboard with the best documentation should win. Remember that documentation available over the Internet counts.
