[VoxelBoy]

4kx4k textures can easily be displayed even on my Macbook Pro's 9400M card. It does cost a high amount of memory; depending on if and how it's compressed, if it has mipmaps, if it contains an alpha channel etc. it can be anywhere between ~16 and ~64 MBs, but is very doable.

[onemoreact]

Yea, but how many of those 16million pixels can be map'd to the display.

A: Not all that many which is why breaking that up into smaller chunks an enabling a virtual 4k texture without compression is a good idea.