Version: 2018.2
public static int maxCubemapSize ;


Maximum Cubemap texture size (Read Only).

This is the largest size of a Cubemap texture face that is supported by the graphics hardware. Note that even if the GPU could support a large texture size, for example 16384, you could still simply run out of memory if trying to create one (16384x16384x6 texture at 32 bits per pixel is 6 gigabytes of data, which may or may not be available).