What is screen tearing?
Why this is happening?
Screen tearing happens due to mismatched timings between the GPU draw frame speed and the monitor refresh rate.
In other words, it means that your monitor cannot keep up with how quickly frames are being drawn from the GPU, causing two incomplete images from the GPU being drawn on the monitor in one instance.
Does more graphics card memory help me to fix screen tearing?
Turn on V-Sync to reduce screen tearing, or shell out some money to buy a monitor with a fast refresh rate and G-Sync or Free-Sync options if you don’t want the downsides of V-Sync.