A MultiSync® monitor is a display device for computers that is able to display images across a range of different refresh rates, rather than being stuck with one option. The "refresh rate" of a screen refers to the number of times each second that a still image is displayed on it. Higher rates, therefore, are required for more crisp and precise displays of video, especially fast or graphics-intensive videos that may play at many dozens of frames per second. A MultiSync® monitor can be adjusted to synchronize to a wide range of refresh rates, which allows it to function with more graphics cards without being damaged.
The name “MultiSync® monitor” comes from a combination of the words “multiple synchronizations,” which refers to the refresh rate for these devices. A display screen of any kind, whether it is a television or a monitor for a computer, functions through a system that effectively creates still images multiple times per second. Much like viewing the individual frames of a film reel, the brain of someone seeing these images connects them together to see moving pictures and instant, fluid changes on a computer screen. The number of times each second that this image on the screen is changed is called the refresh rate.
This refresh rate happens so fast, it is typically unseen by a computer user sitting in front of the screen. It can sometimes be seen on television programs and movies in which a computer monitor is recorded. The refresh rate of the computer screen can be synchronized differently than the rate at which frames for video are created, and so gaps in the monitor’s refresh are captured on film. This often creates scan lines in the image, though a MultiSync® monitor can be used to potentially avoid this issue.
Most computer monitors made in the mid-to-late 20th Century were fixed synchronization displays. This means that they could only function at a single refresh rate. With the development of more powerful computers, especially improved functionality from graphics cards, this single rate was often considered insufficient. A range of different rates was necessary for one display to function with multiple applications and systems, and so the MultiSync® monitor was developed to achieve this.
“MultiSync®” is a trademark owned by Nippon Electric Company (NEC) Display Solutions, but is often used within the industry as a more general term. A “true” MultiSync® monitor is able to synchronize to a wide range of different frequencies, usually with only a minimum and maximum range. There are some companies that produce monitors, however, that are able to synchronize to a few particular refresh rates and may still be referred to as having multiple synchronizations. If a monitor that is fixed to a certain refresh rate is used with a device that requires a higher frequency, then it can potentially be damaged.