In Settings, you can set the rendering environment for the 3D view.
3D View > Rendering > Settings
This function adjusts the background size of the 3D view.
As the value increases, the background image is enlarged.
This function smoothes the outlines of objects visible in the 3D view.
Smoother processing is possible in the following order: None - FXAA - MSAA 2x - MSAA 4x - MSAA 8x - MSAA 16x.
If your graphics card has low performance, you can set this option to None or FXAA.