It cannot be stressed more that the motherboard is the MOST important part of your computer.It is worth investing in a decent motherboard rather than a CPU (although if financiallyacceptable, both) as your motherboard is what connects different parts of the computertogether. In addition, the difference between a cheap and a nice motherboard is typically around$100 US. A good motherboard allows a modest CPU and RAM to run at max efficiencywhereas a bad motherboard causes high-end products to run only modestly.There are 6 things one must consider in choosing a motherboard, CPU Interface, Chipset, IDEor SATA support, Expansion Slot Interfaces and Other Connectors.CPU Interface The CPU interface is the "plug" that your processor goes into. For yourprocessor to physically fit in the motherboard, the interface must be an exact match to yourprocessor.
Intel currently has two mainstream formats, the older Socket 478 (which is graduallybeing phased out) and the newer Land Grid Array 775, which supports higher end CPU withHT technology due to its more efficeint transfer rate. AMD currently uses two sockets, 754 and939. Socket 754 is being aimed at the value market, with all new performance CPUs beingreleased for Socket 939.Formfactor You must choose a case that your motherboard can fit inside of.Chipset Chipsets are also important as it determines the efficiency of RAM and Expansionslots Intel 915 supports upto 533MHz DDRII RAM Intel 925 supports upto 600MHz DDRIIRAMThe functions of BIOS is highly important. Some BIOS features crash proof functions essentialfor updating the firmware. Other motherboards allow BIOS control of overclocking of CPU,RAM and Graphics card which are much more stable and safer for overclocking.IDE (ATA) or SATA interface Older PCs have the two IDE interface which are parallel 44pin connectors but as the motherboard cannot access two devices connected on the same IDEport simultaneously, this has caused a drawback in speed of hard drives and DVD-drives. Thenewer serial ATA (SATA) interface has 4 separate slots that allow independent access and thusincreases the speed of which hard drives work.Expansion Slot Interfaces Old motherboards have the following slots:•AGP - for graphics cards (ranging from AGP 1x, 2x, 4x and 8x)•PCI - for expansion cards and obsolete low end graphics cardsDue to the evolution of new graphics cards on the serial PCI-Express Technology, currentnewer motherboards have the following connections:•PCI-Express 16x - for mainstream graphics cards (4 times speed of AGP 8x)•PCI-Express 1x - for faster expansion cards (replacing older PCI)•PCI - for use of old expansion cards (would be phased out)Older AGP 8x graphics cards are generally being phased out for PCI-Express 16x, as the speedand efficiency is about 4 times that of the AGP 8x technology. Old PCI cards are either nowbuilt into the motherboard (for sound cards, LAN cards, IEEE 1394 firewire and USB 2.0interfaces) or becoming PCI-Express variants.Other Connectors Some considerations for other connectors and expansions include•USB - the number and version of USB connectors (USB 1.0, 1.1 or 2.0)•On-Board Sound Card - Stereo, 3.1, 5.1, 6.1, 7.1, 8.1•On-Board Graphics Card (Phasing Out)•On-Board Base 100 LAN Card•Serial COM or Parallel Printer Ports•On-Board IEEE 1394 FirewireI would suggest at least 4 USB 2.0 ports for high speed access. On-Board Graphics cards aregenerally becoming obsolete as they cannot match the newer PCI-Express 16x technology,especially for gaming where high cooling and efficiency is required.Most motherboards also come with onboard sound. Onboard sound is more than enough formost users, although if you are particular about audio quality or plan to use your computer torecord high-end audio, you may prefer to use a dedicated sound card (preferably PCI-Express1x). Some high-end motherboards support on-board 5.1 Channel Dolby surround sounds so thismay also be a consideration.Onboard graphics are very acceptable for anyone not playing 3D games or using 3D graphicsapplications. Onboard graphics will use a small amount of system RAM as graphics memory(often called shared memory). Purchasing a motherboard with a built-in graphics card is aneasy way to save money for an office computer.If you want gigabit Ethernet, you should purchase a motherboard with the feature built in. Bybeing built into the motherboard, it will have a faster link to all your components than it wouldthrough a PCI expansion card. Also, if you'd like to import Digital Video (DV) onto yoursystem, many motherboards offer onboard FireWire ports.If you are upgrading an older computer, keep in mind the motherboard's number and type ofexpansion board slots.