Most personal computers comes installed with some sort of graphics processing unit. (GPU). Basically the graphics processing unit controls the quality of display shown on the monitor screen. 

If you use your PC to do soft jobs such as typing or watching HD movies the PC would likely be fitted with an integrated GPU. This type of GPU uses resources from the PCs central processing unit. The main disadvantage of integrated GPUs is that they are not that powerful and when you use a heavier program such as a 3D application the whole system will  slow down.

A dedicated GPU comes with his own processor and VRAM and does not draw resources from the CPU. Your PC will need a dedicated GPU if you’ll be using it for powerful 3D applications  HD video editing and high end video gaming.

Types of GPUs available

There are many types of GPUs available but the two most prominent types are those  made by Nividia or AMD. These two major GPU makers are very good and you can’t choose between them. However, Nividia gpu’s have a slight edge. GPUs come in videos grades and models to suit your needs. There are high-end GPUs and low-end ones. Things to look out for when purchasing a suitable GPU includes:

1. Video memory or VRAM: the more powerful a GPU is, the more VRAM it will have. Also check the VRAM speed too; The higher the better.
2. Clock speed and memory bus: as with the VRAM, the higher the processor speed and amount of memory bus the better the GPU is.
3. Size: high-end GPUs are very large in size. Take note of this, you must purchase a GPU that can conveniently fit inside your PC.

Modern graphics card or GPU can be expensive and quite intimidating to look at. Here is a brief explanation of parts of a standard high end  GPU so that you can be more comfortable handling one.

Referring to the figure above

1. PCIE connector: along the bottom of the card is the connector for the PCIe x 16 socket on your motherboard. It must be firmly seated into the motherboard and will be held in place by a clip or slide on the socket
2. Output ports: this port enable you to connect your monitor to the graphics card. Modern graphics cards now have in addition, the DVI and HDMI ports.
3. Exhaust Vent: the exhaust vent helps to get some of the massive amounts of heat generated by the card out of the case. Not all graphics cards have vents but most high-end ones do.
4. Cooling fans: if your GPU is a powerful one it must be fitted with fans in addition to the heat sink. In other words not all GPUs come fitted with fans.
5. Cross switch connector: cross switch connector is used to connect to another GPU. Not all high-end GPUs come with this kind of connector.
6. Power supply port: many modern graphics cards now have their own separate power connection, separate from the power that goes to the motherboard.
7. Speed controller switch: this is the fan speed controller switch. It is used to manually control the fan speed.

The power supply unit PSU is often the most overlooked component of the PC. It is also the component that usually first develops a fault. When purchasing a PSU, make sure it has enough capacity to power all the components of your PC and with a little to spare. The PSU should have enough capacity to power the CPU, GPU, HDD,  CD drive,  motherboard and with a little to spare in case of an upgrade.

To know the PSU capacity you should buy, add up the power requirements of all major components of your PC, will give you a great idea of the power capacity ups you should have.

Modern power supply units for PCs are usually rated between 1000 to 1500 Watts.

Types of PSU

The two types of PSU out there are the wired and  the modular PSU. The wired PSU comes with connecting  wires attached permanently to the  power unit. The modular PSU comes with connecting wires detached from the power unit, you only plug the ones that are needed. The modular PSU is more expensive due to the convenience it provides.

Power connectors

This refers to the connecting wires from the power unit to the PC components. It is your duty to check that the power unit you have purchased has the correct connecting wires and pin mouths to attach to your PC components such as the CPU, GPU  CD-ROM , DVD and so on.

20 + 4 pin connector:

this is the connector for the motherboard. Your motherboard may come with a 20 or 24 pin connector.

The 4+4 pin connector:

this is the connector for the CPU, it can either be a 4 pin or 8 pin connector.

PCIE 6 Pin Connector:

this is a dedicated connector for modern GPUs. Older GPUs draw their power from the motherboard.

Molex connector:

this connector is used to provide power to the hard drive and the CD drive. Nowadays this connector has been replaced by SATA connectors.

SATA connectors:

these are the latest connectors for hard disk drives and optical drives.