This is not needed anymore and causes issues with alphas_cumprod.

comfy/sd.py

@@ -1159,9 +1159,6 @@ def load_checkpoint_guess_config(ckpt_path, output_vae=True, output_clip=True, o
     else:
         model = model_base.BaseModel(unet_config, v_prediction=v_prediction)
 
-    if fp16:
-        model = model.half()
-
     model = load_model_weights(model, sd, verbose=False, load_state_dict_to=load_state_dict_to)
 
     return (ModelPatcher(model), clip, vae, clipvision)