Each pixel will be composed of 256 sub-pixels, arranged 16x16. This will give 256x spatial resolution, or 16x linear resolution. Normally, you'd also set size to x16.
Each pixel will be composed of 64 sub-pixels, arranged 8x8. This will give 64x spatial resolution, or 8x linear resolution. Normally, you'd also set size to x8.
Each pixel will be composed of 16 sub-pixels, arranged 4x4. This will give 16x spatial resolution, or 4x linear resolution. Normally, you'd also set size to x4.
Each pixel will be composed of 4 sub-pixels, arranged 2x2. This will give 4x spatial resolution, or 2x linear resolution. Normally, you'd also set size to x2.