[header] How to buy a high performance video card [title] Understand the graphical processing unit. [step] The gpu is the most important part of a video card, as it performs all of the calculations necessary to display beautiful, real-time graphics on your screen. A gpu's strength is measured in clock speed, notated with " hertz " as its unit of measurement.
In general, the higher the clock speed, the more power it has. Upper tier gpus will have a clock speed between 700 and 800 mhz.