# Flux Schnell and no support dtype

**URL:** <https://forum.comfy.org/t/flux-schnell-and-no-support-dtype/678>\
**Category:** Mac\
**Tags:** issue, model-support\
**Created:** [December 1, 2024, 2:55pm UTC](https://forum.comfy.org/t/flux-schnell-and-no-support-dtype/678 "2024-12-01T14:55:15Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![dobunzli](https://avatars.discourse-cdn.com/v4/letter/d/eada6e/32.png) [@dobunzli](https://forum.comfy.org/u/dobunzli)\
**Post date:** [December 1, 2024, 2:55pm UTC](https://forum.comfy.org/t/flux-schnell-and-no-support-dtype/678/1 "2024-12-01T14:55:15Z")

</div>

```auto
loaded completely 0.0 11340.311584472656 True
  0%| | 0/4 [00:00<?, ?it/s]
!!! Exception during processing !!! Trying to convert Float8_e4m3fn to the MPS backend but it does not have support for that dtype.

```

Apparently if you can add `PYTORCH_ENABLE_MPS_FALLBACK=1 python3 main.py` so that it uses the CPU that would work, but I cannot find where or how to input this parameter in ComfyUI Desktop. Can you help ?

Moreover some people are able to make it work see for instance here: [Kijai/flux-fp8 · Can this model be used on Apple Silicon?](https://huggingface.co/Kijai/flux-fp8/discussions/14)

So is this something that could be fixed in ComfyUI V1 Desktop ?  
Thanks for your answers !

---

<div class="post-metadata">

**Author:** ![dobunzli](https://avatars.discourse-cdn.com/v4/letter/d/eada6e/32.png) [@dobunzli](https://forum.comfy.org/u/dobunzli)\
**Post date:** [December 6, 2024, 10:13pm UTC](https://forum.comfy.org/t/flux-schnell-and-no-support-dtype/678/2 "2024-12-06T22:13:53Z")

</div>

Hello, any news or ideas on this ? Thanks.