LAS VEGAS—At CES 2014, Nvidia is demonstrating an interesting new display technology that it first announced back in October. Called G-Sync, it’s a circuit board that display manufacturers mount inside the monitors they sell—it can’t be added to an existing display. The board eliminates annoying visual artifacts such as tearing and stuttering by synchronizing the display’s refresh rate to the video card’s output.
Today’s video displays have a fixed refresh rate, such as 60-, 120-, or more cycles per second. That’s perfectly fine when you’re watching a video, because its frames arrive at the display in lockstep with the display’s refresh rate. But when you’re playing a game, the video card outputs each frame as soon as it’s rendered. So its refresh rate is highly variable, because some scenes take longer to render than others.
If the card sends a new frame to the display while the display is in the middle of a refresh, the image might tear, with horizontal lines appearing across the image. It might last only a fraction of a second, but your eye and your brain will pick it up and it will distract from your enjoyment of the game.
The old solution for this problem was to enable VSync in either the game’s settings or in the video card’s control panel. This prevents the video card from sending a new frame to the display until the next refresh period. But that can result in stuttering, because one frame might be displayed twice while the monitor waits for a fresh one to be rendered.

Asus’ Republic of Gaming Swift PG278Q monitor includes G-Sync technology.
I saw the new tech demoed last night at Nvidia’s booth on Asus’ new Republic of Gaming Swift PG278Q monitor, and at the Philips booth on that company’s equally new 272G5DYEB monitor, and it looks very impressive. The G-Sync board in the monitor communicates with the video card in the PC, preventing the monitor from refreshing until the video card is ready to send it a new frame. It synchronizes the display to the video card so that both components refresh at exactly the same time. The result: No tearing and no stuttering.
Asus expects the Asus PG278Q to fetch $799 when it ships in the second quarter. Philips has priced its 272G5DEYB at $649 and expects it to be available in the same time frame. Both displays are 27-inch panels with native resolution of 2560 by 1440 pixels.