We heard the words screen tearing thrown around quite a lot during the PS3 / Xbox 360 generation of games consoles. Not everyone knew what it was but we knew that it was a negative attribute if a game had it. So here’s a break down of what screen tearing is.
Screen tearing is an effect that occurs on a video source where 2 frames of video are shown together in a single frame causing a torn effect. This is most visible on straight objects like trees where the previous frame will be behind the next frame when the camera moves along the x axis.
Screen tearing is caused by the video frames being out of sync with the display device. When the refresh rate of the device doesn’t match that of the display device it causes the frames to sync up incorrectly causing the tearing effect. This often occurs in video games when the GPU of the system is under pressure from large amounts of graphical processing or poor programming, This will cause a sudden dip in the frame rate. When the GPU is under a lot of pressure it will fail to keep the output video in sync causing the screen to tear.
Unfortunately due to the lack of power it was difficult for a lot of developers to fix any screen tearing problems with consoles from the PS3 / Xbox 360 generation. With the arrival of the Ps4 and Xbox one there is now more power available to developers to be able to fix screen tearing. V-sync is a term that developers have been using a lot lately when addressing screen tearing problems. “Vertical synchronization is where the video card is prevented from doing anything visible to the display memory until after the monitor finishes its current refresh cycle.” This will prevent the 2 devices every falling out of sync.
V-sync solves the problem of screen tearing but it comes with some drawbacks such as input lag and judder which is caused when the video source misses the monitors refresh deadline. This means frames dont get displayed on time resulting in a jumpy judder effect when the video is viewed on the screen.
NVidia have developed a new technology that is said to fix screen tearing while minimizing the side effects or drawbacks associated with v-sync. NVidia G-SYNC technology works by syncing the displays refresh rates to the graphics card resulting in a smooth screen tear free experience. Read more about G- SYNC.