What Refresh Rate Means: 60Hz, 120Hz and Beyond
Refresh rate is how many times per second a screen updates its picture. See how it differs from frame rate, what common figures mean, and what variable refresh rate does.
In this article
Refresh rate is the number of times per second a screen shows a new image, measured in hertz (Hz). A 60Hz screen updates 60 times a second and a 120Hz screen 120 times. A higher number allows smoother motion, but only if the content being shown actually has enough frames to use it.
Refresh rate versus frame rate
These two terms are easy to mix up. Refresh rate belongs to the display: how often it can put up a new picture. Frame rate belongs to the source: how many images a game, film or video produces each second, usually written as frames per second (fps). Wikipedia's article on refresh rate stresses that the two can differ. Display Ninja puts it plainly: a higher refresh rate lets a display handle a higher frame rate, but does nothing if the source never goes above the display's current rate.
Samsung's monitor guide makes the same point: if a system cannot consistently produce enough frames to match the monitor, you may not see much improvement.
Common figures
Wikipedia lists common monitor refresh rates of 50, 60, 75, 100, 120, 144, 200 and 240 Hz. Samsung names 60, 120, 144, 240 and 360 Hz as common. Televisions were long built around 60 Hz in regions that used the NTSC standard and 50 Hz where PAL or SECAM was used, and Wikipedia says many high-end LCD TVs now use 120 or 240 Hz (100 or 200 Hz in the 50 Hz regions).
A little arithmetic shows what the number means for timing. At 60Hz a new picture can appear every 16.7 milliseconds (1000 divided by 60). At 120Hz it is every 8.3 milliseconds, and at 240Hz every 4.2 milliseconds.
Flicker on old and new screens
On old cathode-ray tube (CRT) monitors, Wikipedia explains, the glowing coating fades quickly, so the screen must be redrawn constantly, and a low rate produces visible flicker and eye strain. It says smaller CRT monitors are comfortable at 60 to 72 Hz and about 100 Hz is comfortable at almost any size.
Liquid-crystal (LCD) pixels hold their state while powered, so Wikipedia says there is no inherent flicker at any refresh rate. Here the refresh rate instead limits how fast the image can change and the highest frame rate that can be displayed.
What higher rates give you
Samsung says a higher number means smoother transitions and less blur, especially with fast-moving content. Display Ninja calls the step from 60Hz to 120Hz or 144Hz very noticeable in gaming, and notes that a higher refresh rate can lower display latency even when the game runs at 60 fps or less. The gains shrink at the top end, since the source has no frames beyond what the game produces.
When it does not help
- Ordinary video: Display Ninja notes that 24 fps films and 60 fps online video do not need a 120, 144 or 240Hz display
- Games that run at or below 60 fps: a faster screen adds little
- Software that makes extra frames for video (interpolation): some viewers find the result looks artificial
Variable refresh rate
A fixed-rate screen can show "tearing" when the source delivers a frame partway through a refresh: part of the picture comes from one frame and part from the next. Variable refresh rate (VRR) lets the display change its rate on the fly to match what the source delivers. Wikipedia names AMD's FreeSync and Nvidia's G-Sync as implementations, and says VRR can save power and cut input latency in games. Samsung and Display Ninja both say these systems reduce tearing and stutter.
What manufacturers suggest
Samsung's guide, which is from a monitor maker and should be read as such, suggests 60Hz for everyday tasks such as browsing and documents, 75 to 120Hz for smoother video and action-heavy content, and 100Hz or higher for video editing and content creation. For gaming it suggests 100 to 120Hz for casual players on a budget, 144 to 200Hz for most gamers and 240 to 360Hz for competitive players. These are the company's recommendations, not fixed rules, and the right choice depends on the games, the graphics hardware and the budget.
In short: refresh rate is how quickly the screen can update, frame rate is how quickly the content is made, and the smoothness you see is limited by the lower of the two.
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