# 60Hz Vs. 120Hz for Gaming

by Dan Stone

Gamers will probably notice improved picture quality on a TV or monitor that runs a 120Hz refresh rate compared to one that runs at 60Hz. The hertz measurement with TVs and monitors is more practical than it sounds: it tells you how many times the screen refreshes per second. A 60Hz TV displays 60 images every second while a 120Hz TV displays 120. The Hz rating is important for LCD screens and not plasma screens.

## Blur Reduction

The higher HZ rating means the TV is better at reducing motion blur in images. You probably won't notice a difference in picture quality between two TVs running at 60Hz and 120Hz if you are viewing a static image or one with very little movement. Modern video games have a tendency to feature substantial onscreen motion so the higher Hz rating will help even out the image.

## 24/30 Frame Sources

Do you remember the term "common denominator" from your math classes when you were in school? The term applies to TV set frame rates. You probably never thought math knowledge would apply to something like watching TV, but it does now. Most video sources are recorded in 24, 30 and 60 frames per second, with video games typically running at 24 to 30 frames per second. Some video games run at 60 frames per second. The TV set has to replicate the frames multiple times to display 30 frames across 120 screen refreshes. Fortunately, 60 is evenly divisible by 60 and 30; however, it is not divisible by 24. Therefore, a 60Hz TV set has to unevenly divide the 24 frames across 60 refreshes which creates a jagged image. You can divide 120 by 24 evenly, so the 120Hz TV will actually improve the image quality for a lower frame rate source.

## Pans and Zooms

The camera movements known as panning -- moving the camera sideways -- and zooming -- moving the camera view closer or farther from the image -- create a significant amount of motion on the screen. Modern video games often exist in a three-dimensional environment and are constantly redrawing the image across the entire screen similar to panning and zooming. A TV with a 120 Hz refresh rate will display pans and zoom substantially clearer than a 60Hz TV. You may not notice a difference in picture quality with most images on the screen, but the technical superiority is clearly observed with the faster refresh rate.

## Beyond 120Hz

There are TV sets that have higher than 120Hz refresh rates, but the difference is less noticeable than between 60 and 120Hz. The law of diminishing returns applies to the Hz rating. While a 240Hz TV has twice the refresh rate of a 120Hz TV, the viewer may only notice a 15 percent image improvement. On the other hand, if you are playing games on a 3D TV set, you should cut the TV's refresh rate in half because the set has to display two images at the same time. A 240Hz 3D TV has a comparable refresh rate to a traditional 120Hz TV.