It can show faces and texture using any of Direct3D 9, Direct3D 11, or OpenGL. This can make it easier to know the shape visually.
A GPU is used by any display mode, and various problems might occur because of trouble or the compatibility of the GPU driver. In that case, please see FAQ. The latest driver provided from the GPU maker or Windows Update is recommended.
Please use the default render unless you have troubles. The default renderer is Direct3D 11 in most cases, but it varies according to your PC.