Which is more efficient one 8K texture, or four 4K textures?

I know that 8K textures can bog the system down, but if four 4K textures have the same area as one 8K texture, I’m wondering if it’s more memory efficient to divide the UVs into separate textures to avoid an 8K texture size, or if that’s still functionally the same memory-wise. With the issues UDIMs gave me in my last project, I’d rather avoid them if they’re not providing some benefit in this use case.

So basically I’m considering this (one 8k texture):

Or this (two sets of two 4k textures, total area same as one 8K):

Technically, one 8K, if you have enough RAM and GRAM.

I can’t quite tell what you mean: assuming I have the RAM and GRAM for either approach (which I do), are you saying the 8K use more RAM /GRAM or that it uses less and I just need to be sure I don’t go over my system’s RAM/GRAM limit with either approach?

(I don’t use 8K everywhere. Textures for just about anything else will be lower resolution)

This is not about RAM amount. This is RAM to GRAM data transfer issue.

Actually this is important for realtime render engines, but principle is same.

I think that memory requirements will stay the same. If you ran 4x4K using UDIM previously, then there shouldnt be a problem with using 8K.

I more think the real advantage with UDIMs is that each tile doesn’t need to be the same texture size.

I mean unless your character is going to be in a bikini a lot of the time, with close ups of the feet or knees, etc why use a 4K texture when a 2K one on the legs/feet (which are mostly never seen or only seen in a full body shot) would work just fine.

This is why when using UDIM’s you very often see the face/head fill a single tile and maybe the hands filling up half a tile with the arms on the other half and both tiles using 4k textures as those are the parts of the character that are looked at the most and can/do fill a large part of the screen at any given time.

Then the main body and legs/feet can just be 2k textures.


Not planning on a lot of bikini pics but since it’s a base mesh, I like to keep my options open if I ever do. However, I was thinking of it more from the perspective of “I’ll be using smaller textures for distant shots anyway” but your comment did make me realize if the render is a closeup of the face, really don’t need to waste 4K resolution on the legs even if I do want higher res textures on the face for that.

It also occurred to me that in many of the outfits I’m likely to use, I may not need the body texture at all if I adjust the UVs to include the neck/clavicle region with the face, so I’m going to try that.

Bonus, looks like Blender has addressed some of the issues with UDIMs, so my original frustrations may not be an issue anymore. At least, we can bake UDIMs now.

Yup, which I think is the real advantage of UDIM’s, even if it can be a bit of a pain to work with.

We can, I even now have a video about that :smiley:

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