> ## Documentation Index
> Fetch the complete documentation index at: https://dragonwingdocs.qualcomm.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Running on a specific NPU (QCS9075)

The Dragonwing IQ-9075 EVK contains **two powerful NPUs** that can be used for running models.  By default the LLM/VLM models run on **NPU0**, but you have the ability to run the model on **NPU1** as well.

To do this, go into the model directory [you configured during model setup](/ai-workflows/llm-vlm-qcom-setup) and you should see a file called `htp_backend_ext_config.json`<br />\
In this example, we will look at the file `~/models/qwen3_4b_instruct_2507/htp_backend_ext_config.json`:<br />

```json htp_backend_ext_config.json theme={null}
{
    "devices": [
        {
            "soc_model": 43,
            "dsp_arch": "v73",
            "cores": [
                {
                    "core_id": 0,
                    "perf_profile": "burst",
                    "rpc_control_latency": 100
                }
            ]
        }
    ],
    "memory": {
        "mem_type": "shared_buffer"
    },
    "context": {
        "weight_sharing_enabled": true
    }
}
```

To specify which NPU to run on, add the `"device_id"` line below and set to `0` (NPU0 - default) or `1` (NPU1) before starting the container.

```json htp_backend_ext_config.json configured to NPU1 theme={null}
{
    "devices": [
        {
            "device_id": 1,
            "soc_model": 43,
            "dsp_arch": "v73",
            "cores": [
                {
                    "core_id": 0,
                    "perf_profile": "burst",
                    "rpc_control_latency": 100
                }
            ]
        }
    ],
    "memory": {
        "mem_type": "shared_buffer"
    },
    "context": {
        "weight_sharing_enabled": true
    }
}
```

<Note>
  This will only work on the IQ-9075 EVK as it has dual NPUs.  Devices such as the RB3 Gen2 Vision Kit and the RUBIK Pi 3 only have a single NPU, so this section does not apply.
</Note>