A PC’s graphics card takes data from the computer’s processor and uses it to generate (or render) images on your screen. Together with a PC’s processor, the graphics card (also known as video card, graphics processing unit or GPU) has the biggest impact on your PC’s performance. If you use your PC for visually demanding tasks such as CAD, photo/video content creation or gaming or if you work with multiple displays you might benefit from a dedicated graphics card.
There are two main classes of graphics card; consumer cards designed for lightweight content creation and more powerful GPUs intended for workstations and heavy duty applications such as scientific computation and AI work. The two leading GPU manufacturers are AMD and NVIDIA. Both offer a wide range of graphics cards ranging from entry level GPUs to high-powered graphics cards.
The type of graphics card you need will primarily be determined by the type of applications you need to run but there are other important considerations to factor prior to purchase. You should always ensure your graphics card matches up with your monitor’s resolution. The higher the resolution of your display, the more powerful the GPU needs to be to pump out all those additional pixels without stuttering or screen tearing, particularly when playing games with fast refresh rates.
Make sure your PC has enough space for the graphics card you’re considering. Tower PCs generally have enough room to fit the largest, most powerful GPUs as well as the airflow or cooling required to deal with the considerable heat they generate. Small form factor PC models will be more limited though so check for motherboard compatibility before buying. Your PC also needs to have a power supply (PSU) that can provide enough power to the card. Check the PSU’s maximum wattage against the GPU’s required power specs. Low end graphics cards may draw their power directly from the PCI slot whereas midrange and high end models will need to be connected to the PSU via either a six or eight pin cable that is normally included with the PSU by the PC manufacturer.
Depending on the number and type of monitors you plan to connect to your PC, you’ll want to check which ports and connectors the graphics card is equipped with. Most cards have multiple DisplayPorts and at least one HDMI port. Some older cards come with older DVI ports as well. Make sure the GPU you buy has the connectors required for your monitors so you can avoid buying adapters or new screens.
Moving on to a graphics card’s core specs, there are several key ones to be aware of starting with clock speed. Measured in MHz, clock speed measures how quickly the GPU works. Theoretically, the higher the GPU’s speed, the more powerful the card but don’t look at clock speed in isolation; core counts, memory speed, cooling capability and GPU architecture all also have a bearing on performance.
Graphics cards come fitted with their own dedicated RAM which they use to store image data for processing. The amount of RAM varies across different GPU models but the bigger the video RAM (or VRAM) capacity the better the card will be, particularly for complex rendering jobs for example.
Take note of the graphics card’s thermal design parameter (TDP) which measures heat dissipation and also indicates the power wattage the card will require to run. The TDP figure is mainly useful when comparing different GPUs to check which one requires more power.
Finally, if you’re shopping for a graphics card for gaming, some of the latest and greatest graphics cards now support ray tracing. If you’re not sure what that means, it’s an advanced way of rendering light and shadows so that they appear more realistic and lifelike. It requires a lot of computing power and there are currently only a few games that use it. If you want to buy a gaming GPU with one eye on the future though, look for one that supports ray tracing.