Reply To: Texture resolution: explained why powers of 2
It’s been a while but I was answering a question for a client who stumbled upon my page.
The question was in regards to whether or not you should use a single 4K image or two 2K images in your UV map.
Short answer: If you double the image size(i.e. from 2K to 4K) you end up quadrupling the required resources for the increased resolution on the image. Mainly because the pixel count increases by 4 times.
Resources Rule of thumb: file size in memory for a PNG of the image (PNG24 value) go ahead and double it for the live resources needed to handle it.
This website explains it better than I can and they even have a fancy calculator.
https://www.scantips.com/basics1d.html