Many computer motherboards come with on-board graphics which is fine if you only use your PC for browsing the web, e-mailing, or word processing. If you intend to play the latest games, video editing, or just want to increase the performance of your computer then you will want a Graphics Card.
A Graphics Card plugs into an expansion slot on the motherboard. On an older motherboard it may have an old AGP (Accelerated Graphics Port
), and a newer motherboard will have a PCIe x16 (Peripheral Component Interface Express
Graphics Cards - PCIe and AGP
The Graphics Card contains a Graphics Processing Unit (GPU) which performs all the graphics calculations. This frees up the CPU (Central Processing Unit
) to perform other tasks. A Graphics Card also contains its own dedicated memory which is fast and doesn't require any system RAM. Like the CPU, the GPU gets hot and is cooled by a heatsink and usually a fan.
There is usually a selection of ports on the Graphics card which allow you to connect to a monitor. The most basic is the VGA (Video Graphics Array
) port which sends a low quality analogue signal to the monitor. The DVI (Digital Visual Interface
), and HDMI (High Definition Multimedia Interface
) port are more common today as they send a much better digital signal to the monitor. There are three main types of DVI ports including DVI-D which is digital only, DVI-A which is analogue only and DVI-I which combines both digital and analogue. The HDMI port is also digital but includes an audio signal if required for your monitor speakers.
The latest port which is intended to replace VGA, DVI, and HDMI is called 'DisplayPort' which can be found on the latest Graphics cards and Monitors.
Which Graphics Card should i get?
First, see if your motherboard supports the older AGP or the newer PCIe Graphics cards. Your computer/motherboard manual should tell you this or look inside the computer case to see which expansion slots are available.
AGP and PCIe x16 expansion slots.
The photograph above shows two motherboards. The older motherboard (on the left
) has a brown AGP slot along with five PCI slots. The newer motherboard (on the right
) has a PCIe x16 slot along with two PCIe x1 slots and a single PCI slot.
If your motherboard has an AGP slot then you will need an AGP Graphics Card, or if your motherboard has a PCIe x16 slot then you will need a newer PCI Graphics Card.
Nvidia, and AMD/ATI (ATI was acquired by AMD in 2006) are the two main manufacturers of Graphics cards. They both make decent Graphic Cards and the one you choose depends on your personal preference.
The length of a Graphics Card varies considerably from about 7 inches (180mm) to over 12 inches (305mm) long. You need to make sure that there is enough room inside your computer case to fit the card that you want to buy. Another consideration is the width of a Graphics Card as many have a large heatsink and fan and it is likely that it will obscure the adjacent expansion slot making that slot unusable.
Todays powerful Graphics Cards require a fair amount of power and it is important to check if your Power Supply Unit (PSU
) will be able to supply enough power (wattage
). The Graphics card manufacturer's website should inform you as to what the power requirements are, and will recommend the card to be used with a certain wattage PSU or above. More information on Power Supply Units including their wattage can be found here.
A modern Graphics Card may also require power to be connected directly to the card with a 6 or 8 pin connector.
Nvidia, and AMD/ATI are very competitive and are releasing faster and more powerful Graphic Cards all the time making it impossible to list the best cards in this article. Generally, the more you pay for a Graphics card then the better it will be but it is best to look at an up-to-date review site such as 'Tom's Hardware'
that features charts, and reviews on the latest hardware as well as a Forum if you need expert advice. Click here
for Graphics Card comparison chart.
The specification of a Graphics Card includes GPU clock speed, memory, fillrate, and DirectX support. The GPU Clock speed is the speed of the Graphics processor core. The memory specification should include the type (GDDR5 or GDDR7 etc), the speed or clock frequency, the bandwidth (GB/s), size of the memory bus (bits), and the amount of memory. The fillrate is the maximum theoretical fillrate in textured pixels per second and the higher the better. It should also tell you the maximum version of DirectX software that is supported.
Drivers and Software.
When you purchase a Graphics Card then it should come with a driver, and usually some software. The driver is required so that the operating system can communicate with the Graphics Card hardware. It is recommended that you visit the manufacturer's website to obtain the very latest driver for your card rather than using a Windows driver or an out-of-date driver. Included software usually lets you tweak all the graphics settings in detail.
Dual Graphics cards.
If you are an avid gamer who demands the fastest frame-rate in the latest 3D games then you might consider adding two Graphics cards but your motherboard will need to support this. More information can be found here.