with that much detail in the sculpt , I'd expect there to be quite a difference so there's got to be something else going on. might be worth uploading some pictures of the bakes / renders
It could be that the combined 8k texture is sufficient enough to capture all the information in your sculpt? Pixelpeeping the renders, it does look like there is more crisp definition in the higher frequency details (crackly bits in the scales around it's lips) At 8k for a udim of just the head, you're most likely needing…
important point A: UDIM is nothing more than a naming convention, the mechanics of how the result is handled are entirely down to the renderer/engine/whatever. to the original question... images would really help diagnose the problem. if you use a single 4k map and you lose no detail compared to your sculpt then using 10…
Here you go, I've attached some files of the WIP sculpts in Arnold. The top model is the one with only 1 UV tile, the bottom has 10. I also shared the 1 UV tile layout vs the first tile layout of the 10-UDIM version. Essentially his head covering a whole tile vs just a small portion of it. I'm not disappointed with the…