What Graphics Hardware Does
Everything you see on a computer screen is drawn by graphics hardware. The processor decides what should appear, and the graphics hardware turns that into the pixels sent to the display. For simple pictures such as a document or a web page, this is easy work. For complex scenes with many moving, lit and textured objects, it is a very large amount of work, and that is where graphics hardware differs most between computers.
A graphics processor, often called a GPU, is built to do many small calculations at the same time. That suits drawing a picture, where millions of pixels each need their own calculation. It also suits some other jobs with a similar shape, such as certain video and image processing tasks.
Two Kinds: Integrated and Dedicated
Computers come with one of two broad kinds of graphics hardware, and some have both.
Integrated graphics are built into the main processor or the motherboard’s chipset. They have no memory of their own, and instead borrow a portion of the computer’s regular memory. They use little power and produce little heat, and they add almost nothing to the cost.
Dedicated graphics are a separate component with their own graphics processor and their own fast memory, usually called video memory. In a desktop it is typically a card in an expansion slot. In a laptop it is a smaller chip soldered to the board. It generally uses more power, creates more heat, and costs more.
When Built-In Graphics Are Enough
For many people, integrated graphics handle everything they do. Typical tasks that work well on them include:
- Web browsing, email and office documents
- Streaming video, including high-definition video
- Video calls
- Photo viewing and basic editing
- Light or older games, often at reduced settings
Modern integrated graphics are considerably more capable than those of years past. If your use looks like the list above, a separate card is usually money and power that you do not need. It also keeps the computer quieter and cooler, which matters in a small desktop or a thin laptop.
What a Separate Graphics Card Adds
A dedicated graphics card adds two main things: more processing power for graphics, and its own pool of video memory that does not compete with the rest of the computer.
That extra capability is mostly useful for:
- Recent 3D games, especially at higher resolutions or with detailed settings. The topic of how smoothly a game runs is covered in frame rate and stutter, and what the options in a game menu do is covered in graphics settings.
- Video editing and 3D modeling, where previews and exports can lean heavily on the graphics processor, depending on the software.
- Some creative and technical software that can use the graphics processor for extra calculations.
- Driving several or high-resolution displays smoothly, although integrated graphics often manage a couple of ordinary screens perfectly well.
Whether you need these things is a question about your own use, not about prestige. A dedicated card that sits idle while you browse the web is simply a more expensive way to browse the web.
Video Memory in Plain Terms
Video memory holds the textures, images and other data the graphics processor is working on. If a game or program needs more than the card has, the computer must fetch data from slower places, which can cause stutter or force lower settings. Having a larger number is not automatically better, though. A card with plenty of memory but a weak processor still draws slowly. The two need to be reasonably balanced, and the memory amount only becomes the limit in demanding situations.
This video memory is separate from the computer’s main memory. Adding ordinary memory to a computer does not increase the video memory on a dedicated card, and the relationship between the processor and ordinary memory is explained in its own article.
Connecting Your Screen
Graphics hardware has its own output ports, and the picture reaches your screen through a cable. If you have a dedicated card in a desktop, the monitor should usually be plugged into the card, not into the motherboard’s ports, or the computer may keep using the integrated graphics. This is a common and easily fixed mistake. The kinds of cables you might use are described in display cables, and the measures of how sharp and how smooth a picture can be are covered in screen resolution and refresh rate.
Practical Cautions
Graphics cards draw significant power and give off heat. A desktop needs a power supply that can supply enough electricity for the card, with the right connectors, and a case with enough room and airflow. Check the card maker’s stated requirements before buying, because they differ from model to model. Keep the case free of dust, as explained in cleaning a computer safely.
Fitting a card means opening the case and handling static-sensitive parts. Follow the manufacturer’s official instructions, turn the computer off and unplug it first, and back up your files beforehand as a general precaution. A laptop’s dedicated graphics generally cannot be changed at all.
Drivers are the software that lets the operating system make use of the graphics hardware. Problems such as a flickering screen or the wrong resolution are sometimes driver-related, and device drivers explained introduces the idea. Download updates only from the computer or graphics maker’s official site.
Making a Sensible Choice
Start with what you do. If it is everyday browsing, documents and video, integrated graphics are very likely sufficient. If you play recent 3D games or do graphics-heavy creative work, look at what the program or game lists as its requirements, and read how those listings are phrased in reading game system requirements. Spending a little less than the maximum often gives most of the benefit.