Is it possible not to render the part of screen space?

Hello. Is it possible not to render the part of screen space? I have widget which is covering a part of screen so for optimization purpose I want not to render image under it.

Can’t do this. The UI is rendered separately from the rest of the frame. If you made the UI part of the 3D scene then it could occlude other geometry but this would only improve the pixel shading performance and probably not by enough to be worth the hassle in most cases.

But can I just not to render for example 700 pixels from left side of screen? Without interactions with UI.