Graphics cards play an important role in the performance of your computer. They take the burden of graphics processing off of the CPU and provide much better image quality and functionality.
Basically, your CPU sends information about an image to the GPU and it decides how to display it on the screen. It uses a special type of RAM called video RAM that is built for high speed reading and writing of large amounts of data. This RAM is able to store images, textures and other visual information that are needed for rendering them on the screen. It also performs calculations in parallel to make sure that the image is displayed quickly.
If your computer didn’t have a dedicated graphics card, the CPU would have to handle all the graphics-related calculations for each image on its own, which could be too taxing for the system. As screen resolutions have increased, the demands on the GPU have also increased. To make a simple 2-D or 3-D image, the GPU starts by creating a wire frame out of straight lines and then rasterizes it (fills in the pixels). It then applies color, lighting, texture and other effects. These processes can occur 60 to 120 times per second for fast-paced games.
A good graphics card should have a lot of memory that is used to store the images and textures it needs for rendering them on the screen. Typically, this is measured in gigabytes (GB). A larger amount of memory typically means faster processing and better performance. Some GPUs will use different types of RAM, which makes it hard to compare their performance based on just the amount of memory. Other things to consider include the number of stream processors and CUDA cores that each GPU has.