Chroma support

[tororon1231]

Is Chroma supported in stable-diffusion.cpp?

[stduhpf]

I don't think it will work out of the box, because they modified Flux's DiT block architecture, and the prompt processing is also a bit different. It may not be too difficult to implement though.

[Green-Sky]

Technically it should work now (see #696 ), but I just tried a new version and it performs very poorly and I am not sure why. It might be the schedule (everyone seems to be using beta), but not sure.

This is the best output I could generate using:

bin/sd
--diffusion-model models/chroma-unlocked-v48-detail-calibrated-Q4_0-marduk191.gguf
--cfg-scale 12
-t 8
--t5xxl models/flux-extra/t5xxl_q8_0.gguf
--vae models/flux-extra/ae-f16.gguf
--steps 40
--sampling-method euler # ancestral samplers perform worse
--diffusion-fa
--chroma-disable-dit-mask # required for flash attention on cuda still
-W 1024 -H 768
--vae-tiling
-p "photo of an old dog, sitting on the veranda. It is a sunny summer afternoon with a few clouds. There are humans in the background."
-n "ugly, low quality, blury"

As you can see I had to go real high with the cfg scale and steps to get it somewhat sharp.

Here is cfg lowered to 6:

[stduhpf]

I'm having similar results (with the same kind of flaws) when comparing ComfyUI-zluda (with the recommended workflow) and sdcpp (rocm) with the same prompts and settings. I guess it probably has something to do with the model not being quite done training.

Maybe --chroma-disable-dit-mask hurts the model more than we initially thought too.