use half() on fp16 models loaded with config.

comfy/sd.py

@@ -733,6 +733,12 @@ def load_checkpoint(config_path, ckpt_path, output_vae=True, output_clip=True, e
     scale_factor = model_config_params['scale_factor']
     vae_config = model_config_params['first_stage_config']
 
+    fp16 = False
+    if "unet_config" in model_config_params:
+        if "params" in model_config_params["unet_config"]:
+            if "use_fp16" in model_config_params["unet_config"]["params"]:
+                fp16 = model_config_params["unet_config"]["params"]["use_fp16"]
+
     clip = None
     vae = None
 
@@ -754,6 +760,10 @@ def load_checkpoint(config_path, ckpt_path, output_vae=True, output_clip=True, e
     model = instantiate_from_config(config["model"])
     sd = load_torch_file(ckpt_path)
     model = load_model_weights(model, sd, verbose=False, load_state_dict_to=load_state_dict_to)
+
+    if fp16:
+        model = model.half()
+
     return (ModelPatcher(model), clip, vae)