AMD GPU --directml --lowvram error

my GPU
RX 6600
i want lowvram option

run
```
.\python_embeded\python.exe -s ComfyUI\main.py --windows-standalone-build --directml --lowvram
```
than
```
!!! Exception during processing !!!
Traceback (most recent call last):
File "C:\ComfyUI_windows_portable2\ComfyUI\execution.py", line 145, in recursive_execute
output_data, output_ui = get_output_data(obj, input_data_all)
File "C:\ComfyUI_windows_portable2\ComfyUI\execution.py", line 75, in get_output_data
return_values = map_node_over_list(obj, input_data_all, obj.FUNCTION, allow_interrupt=True)
File "C:\ComfyUI_windows_portable2\ComfyUI\execution.py", line 68, in map_node_over_list
results.append(getattr(obj, func)(**slice_dict(input_data_all, i)))
File "C:\ComfyUI_windows_portable2\ComfyUI\nodes.py", line 1082, in sample
return common_ksampler(model, seed, steps, cfg, sampler_name, scheduler, positive, negative, latent_image, denoise=denoise)
File "C:\ComfyUI_windows_portable2\ComfyUI\nodes.py", line 1052, in common_ksampler
samples = comfy.sample.sample(model, noise, steps, cfg, sampler_name, scheduler, positive, negative, latent_image,
File "C:\ComfyUI_windows_portable2\ComfyUI\comfy\sample.py", line 75, in sample
comfy.model_management.load_model_gpu(model)
File "C:\ComfyUI_windows_portable2\ComfyUI\comfy\model_management.py", line 302, in load_model_gpu
accelerate.dispatch_model(real_model, device_map=device_map, main_device=torch_dev)
File "C:\ComfyUI_windows_portable2\python_embeded\lib\site-packages\accelerate\big_modeling.py", line 373, in dispatch_model
attach_align_device_hook_on_blocks(
File "C:\ComfyUI_windows_portable2\python_embeded\lib\site-packages\accelerate\hooks.py", line 527, in attach_align_device_hook_on_blocks
attach_align_device_hook_on_blocks(
File "C:\ComfyUI_windows_portable2\python_embeded\lib\site-packages\accelerate\hooks.py", line 527, in attach_align_device_hook_on_blocks
attach_align_device_hook_on_blocks(
File "C:\ComfyUI_windows_portable2\python_embeded\lib\site-packages\accelerate\hooks.py", line 497, in attach_align_device_hook_on_blocks
add_hook_to_module(module, hook)
File "C:\ComfyUI_windows_portable2\python_embeded\lib\site-packages\accelerate\hooks.py", line 155, in add_hook_to_module
module = hook.init_hook(module)
File "C:\ComfyUI_windows_portable2\python_embeded\lib\site-packages\accelerate\hooks.py", line 253, in init_hook
set_module_tensor_to_device(module, name, self.execution_device)
File "C:\ComfyUI_windows_portable2\python_embeded\lib\site-packages\accelerate\utils\modeling.py", line 165, in set_module_tensor_to_device
new_value = old_value.to(device)
File "C:\ComfyUI_windows_portable2\python_embeded\lib\site-packages\torch\cuda\__init__.py", line 239, in _lazy_init
raise AssertionError("Torch not compiled with CUDA enabled")
AssertionError: Torch not compiled with CUDA enabled
```

run
```
.\python_embeded\python.exe -s ComfyUI\main.py --windows-standalone-build --directml --normalvram
```
than
8GB use vram