What is screen tearing?
Tearing is a visual artefact, represented by a tear in the image. In other words, one or more dividing lines between two or more different images. A dividing line can be positioned anywhere on the image.
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?
No,as i mentioned the real problem results in your monitor which cannot handle the images sent by your graphic card.However a less graphic card memory can fix the problem.
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.