Fix slow performance on 10 series Nvidia GPUs.

Author: comfyanonymous

comfy/model_management.py

@@ -668,6 +668,7 @@ def unet_manual_cast(weight_dtype, inference_device, supported_dtypes=[torch.flo
     if bf16_supported and weight_dtype == torch.bfloat16:
         return None
 
+    fp16_supported = should_use_fp16(inference_device, prioritize_performance=True)
     for dt in supported_dtypes:
         if dt == torch.float16 and fp16_supported:
             return torch.float16