A larger array consumes more memory, but if we assume those textures would’ve been in memory anyway, this is irrelevant. Where you can get into trouble is if you make an excessively large array of textures that results in memory being allocated to textures that aren’t actually in use. I would say rather than four 2k tex performing like one 4k tex, you should think of it as performing like a 2k tex that consumes as much memory as a 4k tex.