Graphics Card

Graphics cards are capable of producing 3D graphics at a much faster rate than CPUs, which make them ideal for gaming and video rendering.

If you are building a system for gaming, it is recommended that you devote the largest chunk of your budget towards getting the most powerful graphics card you can afford as this will have the greatest impact by far on your gaming performance.

Graphics cards connect to the motherboard via PCIe (Peripheral Component Interconnect Express) ports.

Nvidia vs AMD

The two main competitors in the graphics card market are Nvidia and AMD.

I'll write this up later, or someone else can make a start on this in the meantime - Sabine

Coolers

Coolers consist of a heatsink and fans that dissipate heat from the GPU, memory and other components on the card. It is recommended that you buy a card with a good cooler if you wish to overclock, as overclocking creates higher temperatures.

It is recommended that you avoid "Founder's Editions" of graphics cards. These are manufactured directly by Nvidia and AMD and are often the first releases of any new card. They use a blower style cooler in place of the usual open air cooler that aftermarket brands ship with. These are far less effective and often result in higher temperatures.

It is only recommended that you use Founder's Edition cards for multi card setups where all the cards are located very close to one another, as blower style coolers dissipate heat towards the back of the case instead of all around, which would mean just blowing heat towards each other in these setups.

Drivers

Installing the latest drivers is essential for running a graphics card at peak performance. Driver updates often optimise the performance or power efficiency of a card.

Overclocking

Just like CPUs, graphics cards can be overclocked. An average overclock can increase framerates in games by around 10%.

Overclocking a card too much can cause instability and crashes. Overvolting the card can stabilise an otherwise unstable overclock, but will increase the heat generated by the card. At a certain point thermal throttling (decrease in performance caused by high temperatures) will counteract the performance gains from overclocking, so having a good cooler will allow you to overclock further before this limit is reached.

Setting up a custom fan profile can help to lower noise at lower temperatures or increase cooling at higher temperatures.

The recommended overclocking software is currently MSI Afterburner.

After overclocking a card, it is essential to test that your overclock is stable using benchmarking software such as Unigine Superposition or 3DMark Time Spy. Be sure to run these for at least half an hour and watch out for any artifacts (visual glitching) or crashes and instability.

Graphics Processing Unit

The graphics processing unit, or GPU is responsible for performing the bulk of graphical operations.

GPUs differ from CPUs in that they tend to contain vast amounts of weaker cores compared to CPUs which only have a few cores, although each of them are very powerful. This difference means GPUs are great for tasks that can be performed in parallel, such as graphical operations.

Video RAM

Video RAM, or VRAM is specialised memory located on the card, dedicated to storing image data such as textures and shaders.

Having sufficient VRAM is essential for running higher resolution textures in games without incurring a drop in framerate.