Motherboard Specifications for Home Computers

Motherboard

The motherboard is the single most important component of the computer. Many of the decisions for the other parts you purchase need to be based on the capabilities of the motherboard. You need to decide the speed and type of microprocessor you want and then buy accordingly. I always buy the motherboard with the microprocessor already installed, which should alleviate most of the incompatibility problems and special jumper settings. The primary factors to consider in the purchase of the motherboard are the amount of cache memory installed, the type of and amount of memory chips it recognizes, and the number of different types of peripheral slots. If you're getting a 486 board, you're going to want two or three VESA slots and for a Pentium board you're going to want at least two or three PCI slots. ISA boards are being phased out, so you want to make sure your motherboard has several PCI slots and several EISA slots. Some motherboards have things such as the hard disk controller and I/O ports builtin. There are advantages and disadvantages to this. The advantage is that you have more peripheral slots available for other types of cards, the disadvantage comes with the problems encountered if you decide you want a different hard disk controller or I/O port than what the motherboard provides. Don't get a motherboard with builtin video or sound, because there's a much better chance that you're going to want to upgrade or swap out the video and sound at some time.

440LX. The motherboard is where you'll find support chips to perform various functions. If you want to make sure you're not getting a motherboard that's obsolete before you buy it, make sure you get at least a Pentium board with the 430TX chip set or a Pentium Pro or Pentium II board with the 440LX chip set. These chips will allow you to utilize AGP, Ultra DMA 33, APCI, SDRAM, and USB. There's another new technology that is coming down the pike called Fire Wire (IEEE1394). This is a new superfast interface for storage devices, cameras, scanners, imaging, etc. Fire Wire allows up to 67 devices to be daisy-chained together. This technology is still changing, so the support chips aren't available yet to recognize it (in the PC world). I believe the chipset that will support FireWire is the 440BX chipset. (It will also support a 100MHZ I/O bus).

AGP. AGP is the Accelerated Graphics Port. This is a special port on the motherboard specifically for a special graphics board. Don't get a motherboard with the AGP video built-in, because you can only have one instance of the AGP. If you get one built-in, you can't add a new AGP graphics board later. AGP in addition to providing graphics acceleration allows the main RAM to be used in addition to the on-board graphics RAM for various 3D effects. AGP requires Windows 98 or Windows NT 5.0 for full utilization. It's also still evolving, so it may be awhile before you really see much improvement over current video technology. The biggest advantage right now is seen in 3D applications, such as games.

Ultra DMA 33. Ultra DMA 33 is a speed acceleration technique for the EIDE interface. Basically it allows throughput up to 33 MB per second throughput (double normal) using buffers.

FireWire. FireWire (IEEE 1394) is still evolving. You probably won't see much about it until 1999. Motherboards that support it won't be out until the standard stabilizes. FireWire is a very fast bus for high-end devices like hard disks and video-imaging. It's also hot-swappable and allows up to 67 devices to be daisy-chained together. It's coming, but it will be awhile before the price is competive for home computers.

APCI. APCI is Advanced Power and Configuration Interface. Obviously this specification has to do with the power system and the biggest advantage is that it allows your computer to run at a very low power consumption level with just enough power to keep the memory active, so that when you power up the computer, it starts up right where you left off rather than going through a complete bootup cycle. Again the new versions of the operating systems are needed to fully implement the capabilities. Right now, APCI is the only power management specification that Windows NT 5.0 plans to support, plus without APCI for NT, no Plug and Play either.

SDRAM. Synchronous Dynamic Random Access Memory is covered on the Memory page.

USB. Universal Serial Bus is a new specification for connecting peripherals. There should be two USB ports, one on the front of the computer and one on the back. The two biggest advantages of USB are the capability to daisy-chain as many as 127 devices together at a higher rate of throughput than found with either standard serial ports or parallel ports. USB operates at 12 M bps which is slightly faster than an enhanced parallel port. USB devices are also hot-swappable and get away from the dreaded interrupt problem. You will be seeing USB cameras, modems, audio devices, keyboards, game controllers, and other communications and input devices. Most of these devices will become available once Windows 98 provides the drivers.

Other Ports. Most Pentium boards have I/O builtin in to them, 486 boards usually require a separate card. Usually at a minimum you need a serial port and a parallel port. If you need more, they're probably going to be in this order, 2nd serial port, 2nd parallel port, game port. For some people the game port may come first, it all depends on whether or not you need a joystick. I don't use one, so I don't need a game port. The need for a second serial port usually depends on whether you have a serial mouse or PS/2 mouse and whether you have an internal or external modem. The serial mouse and the external modem will each require serial ports.

Make sure you get a book with the motherboard that explains everything and gives the specifications of the connections and sockets. Some major motherboard suppliers are Asus, SuperMicro, Tyan, Intel, and Gigabyte.

There are some good review of motherboards at Anand's Hardware Tech Page, Motherboard HomeWorld, and Tom's Hardware Guide.