intel NPU is so slow

I used Intel's AI Boost, and it's too slow...，NPU uasge 37%

 cd .\transformers-bitnet
 pip install .
 pip install torch accelerate intel-npu-acceleration-library gradio

import torch
import torch._dynamo
torch._dynamo.config.suppress_errors = True
from transformers import AutoModelForCausalLM, AutoTokenizer, TextStreamer
from intel_npu_acceleration_library import NPUModelForCausalLM
from intel_npu_acceleration_library.compiler import CompilerConfig
import gradio as gr
model_id = "microsoft/bitnet-b1.58-2B-4T"


tokenizer = AutoTokenizer.from_pretrained(model_id)
compiler_conf = CompilerConfig( dtype=torch.bfloat16)
# optimized_model = torch.compile(model_id, backend="npu")
model = NPUModelForCausalLM.from_pretrained(model_id, config=compiler_conf,use_cache=True,attn_implementation="sdpa").eval()
prompt = f"<s>用户:{user_input}\n助手:"

inputs = tokenizer(prompt, return_tensors="pt").to(model.device)
streamer = TextStreamer(tokenizer, skip_special_tokens=True)
outputs = model.generate(
      **inputs,
      do_sample=True,
      temperature=0.5,
      top_p=0.85,
      repetition_penalty=1.1,
      streamer=streamer,
      top_k=50,
      max_new_tokens=512
  )

Start by reproducing the issue with the listed installation commands and the Python entry point using NPUModelForCausalLM with microsoft/bitnet-b1.58-2B-4T. Measure generation speed and NPU utilization, then inspect the Intel NPU acceleration path and record a specific bottleneck or reproducible performance result as the outcome.