Renderscale (Slash Command)

Slash Command

/renderscale [0.01-2.0]

Changes the scale at which the 3D world is rendered relative to your screen size.

/renderscale changes the image resolution of the game's 3D world based on a percentage of your display's size. For example, if you had a 1920x1080 screen size, /renderscale 0.5 would set the screen resolution to 50% of your screen's size or 690x540.
1.0 = 100% The default size and resolution of your screen
The /renderscale command changes the resolution of everything that is rendered in 3 dimensions by the graphics card. Conversely, it does not affect 2-dimensional objects rendered by the game such as the chat box or other User Interface (UI) elements.
Use the /userenderscale 1 command first to enable 3D resolution scaling.
This command alters the 3D Resolution Scaling slider in Options--> Graphics and Audio tab.

The command can be made more or less permanent by running it automatically at log-in as a Command Line Parameter. For example,
-renderscale 0.5

/renderscale 0.5