Part three in a series on the basics of building a computer to prepare for the A+ certification exams.
The main circuit board in a computer is called the motherboard. It is also referred to as the systemboard or mainboard (or logic board if you are working in the Apple world). “Mobo” is also a common technical term used to refer to a motherboard. The motherboard is where all the internal components of the computer are connected. Because it can be the most complicated component to purchase when building a computer, you have to pay close attention to a motherboard’s form factor, CPU socket type, and chipset since those things ultimately determines both the capabilities and limitations of your computer.
The Form Factor
The form factor of a motherboard refers to the physical size and shape of the board. The form factor also determines what type of case and power supply will work with a particular motherboard. Most desktop computer motherboards use the ATX standard form factor but there are other form factors that are variations of the ATX (Mini-ATX, Micro-ATX). ITX and BTX are two other motherboard form factors available for modern computers. In addition, some smaller form factor motherboards of the same family will fit larger cases. For example, an ATX case will usually accommodate a Micro-ATX motherboard.
A chipset forms an interface between the CPU’s front-side bus, main memory, and peripheral buses. The chipsets define the capabilities and characteristics of the computer.Basically, the chipset help process and direct data for the CPU. The chipset is designed to support a select few CPUs particular to that motherboard. So you have to make sure the CPU you buy is compatible with the chipsets on the motherboard.
The CPU Socket
A CPU socket type and motherboard chipset must support the CPU series and speed. The CPU socket is basically the connector on the motherboard that houses a CPU. It is keyed to ensure the proper insertion of the CPU. Many CPU sockets use a pin grid array (PGA) package where pins on the underside of the CPU connect to holes in the CPU socket and then a lever is closed to secure the CPU in place. This is known as zero insertion force (ZIF). Alternatively, CPUs with a land grid array (LGA) package are inserted into the socket and then a latch plate is put into place atop the CPU locking it into place.
Other Slots, Ports and Connectors
The motherboard connects everything inside your computer. There are slots for installing RAM as well as expansion slots for installing additional components such as graphics cards and sound cards. Additionally, a motherboard will also have several internal connectors and ports for many integrated components such as SATA drives, VGA, DVI and/or HDMI connectors for an integrated graphics, S/PDIF output for integrated sound, RJ-45 port for 10/100/1000 Mbit networking and connectors for USB 2.0/3.0 just to name a few.
Another important aspect of a motherboard, but not necessarily a major determining factor in purchasing one, is the BIOS. The basic input/output system or BIOS makes sure all the components in a computer function together. In a nutshell, the BIOS is special software, usually stored on a flash memory chip on the motherboard of a computer, that interfaces the major hardware components of your computer with the operating system. The BIOS software has a number of different roles, but its most important role is to load the operating system.
When you turn on your computer, the BIOS does several things during the boot sequence such as check the CMOS (Complementary Metal Oxide Semiconductor) Setup for custom settings, load the device drivers, determine which devices are bootable and perform the power-on self-test (POST). It also displays text describing things like the amount of memory installed in a computer, the type of hard drives and so on.
What I picked
The motherboard for this project is the Gigabyte GA-A55M-DS2
. It has a Socket FM1, which is used by AMD A-series mainstream Fusion (Llano) processors. It’s a good match for the AMD A6-3500 Llano 2.1GHz CPU that I chose. It is based on the AMD A55 chipset and also supports AMD Dual Graphics technology, which allows you to increase graphics performance by adding an additional discrete AMD Radeon HD 6000 series graphics card to the computer. This means that it will utilize the processing power of both discrete and integrated graphics processors. The motherboard has both a PCI Express x16 slot and a PCI Express x1 slot (both PCI Express 2.0 standard). There are four SATA 3Gb/s connectors supporting up to four SATA 3Gb/s devices capable of RAID 0,1,10. Two DDR3 DIMM sockets supporting up to 32 GB of system memory (DDR3 1866/1600/1333/1066 MHz memory modules).
More detailed information about the motherboard is covered under the PC Hardware Domain (1.2) of the 801 exam for the A+ certification.