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# HIGGS

[HIGGS](https://arxiv.org/abs/2411.17525) is a zero-shot quantization algorithm that combines Hadamard preprocessing with MSE-Optimal quantization grids to achieve lower quantization error and state-of-the-art performance.

Runtime support for HIGGS is implemented through the [FLUTE](https://github.com/HanGuo97/flute) library. Only the 70B and 405B variants of Llama 3 and Llama 3.0, and the 8B and 27B variants of Gemma 2 are currently supported. HIGGS also doesn't support quantized training and backward passes in general at the moment.

Run the command below to install FLUTE.

<hfoptions id="install">
<hfoption id="CUDA 12.1">

```bash
pip install flute-kernel
```

</hfoption>
<hfoption id="CUDA 11.8">

```bash
pip install flute-kernel -i https://flute-ai.github.io/whl/cu12.4
```

</hfoption>
</hfoptions>

Create a [`HiggsConfig`] with the number of bits to quantize a model to.

```python
from transformers import AutoModelForCausalLM, AutoTokenizer, HiggsConfig

model = AutoModelForCausalLM.from_pretrained(
    "google/gemma-2-9b-it",
    quantization_config=HiggsConfig(bits=4),
    device_map="auto",
)
```

> [!TIP]
> Find models pre-quantized with HIGGS in the official ISTA-DASLab [collection](https://huggingface.co/collections/ISTA-DASLab/higgs-675308e432fd56b7f6dab94e).

## torch.compile

HIGGS is fully compatible with [torch.compile](https://pytorch.org/tutorials/intermediate/torch_compile_tutorial.html).

```python
import torch
from transformers import AutoModelForCausalLM, AutoTokenizer, HiggsConfig

model = AutoModelForCausalLM.from_pretrained(
    "google/gemma-2-9b-it",
    quantization_config=HiggsConfig(bits=4),
    device_map="auto",
)

model = torch.compile(model)
```

Refer to the table below for a benchmark of forward passes/sec for Llama-3.1-8B-Instruct on a RTX4090.

| Batch Size | BF16 (with `torch.compile`) | HIGGS 4bit (without `torch.compile`) | HIGGS 4bit (with `torch.compile`) |
|------------|-----------------------------|----------------------------------|-----------------------------------|
| 1          | 59                          | 41                               | 124                               |
| 4          | 57                          | 42                               | 123                               |
| 16         | 56                          | 41                               | 120                               |
