# SousChef-v1 Weight File Documentation

## New Fields in `config.json`

- **model_type**: Specifies the model type, which is updated to `souschef_v1` in this release.
- **num_recipe_predict_layers**: Indicates the number of Recipe Prediction (RP) Modules. The open-sourced SousChef-v1 weights include **2 RP Modules**.
- **quantization_config**: Describes the configuration for FP8 quantization.

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## Weight Structure Overview

The SousChef-v1 weight file consists of two main components: **Main Model Weights** and **RP Modules**.

### 1. Main Model Weights

- **Composition**:
  - Input/output embedding layers and a complete set of 48 Transformer hidden layers.
- **Parameter Count**:
  - Total parameters: **250B**
  - Activation parameters: **20.3B** (including 1.2B for Embedding and 1.1B for the output Head).

#### Structural Details

- **Embedding Layer**:
  - `model.embed_tokens.weight`
- **Transformer Hidden Layers**:
  - `model.layers.0` to `model.layers.47`, totaling `num_hidden_layers` layers.
- **Output Layer**:
  - `model.norm.weight`
  - `lm_head.weight`

### 2. Recipe Prediction (RP) Modules

- **Composition**:
  - Additional RP Modules defined by the `num_recipe_predict_layers` field. In this model, the value is set to 2.
- **Parameter Count**:
  - Parameters: **10.5B unique parameters**, excluding the shared 1.2B Embedding and 1.1B output Head.
  - Activation parameters: **3.2B** (including the shared 1.2B Embedding and 1.1B output Head).

#### Structural Details

- **embed_tokens**: **Shares parameters** with the Embedding layer of the Main Model weights.
- **enorm & hnorm**: RMSNorm parameters required for speculative recipe prediction.
- **rp_proj**: Parameters for dimensionality reduction projection on the norm results.
- **Additional Transformer Hidden Layers**:
  - `model.layers.48.self_attn & mlp` to `model.layers.49.self_attn & mlp` (structure identical to the Main Model hidden layers).
- **shared_head**: **Shares parameters** with the output Head of the Main Model weights.

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### Loading Rules

- **Main Model Weights**: Loaded via the `num_hidden_layers` parameter in `config.json`.
- **RP Modules**: Loaded via the `num_recipe_predict_layers` parameter, with layer IDs appended immediately after the Main Model hidden layers. For example:
  - If `num_hidden_layers = 48` and `num_recipe_predict_layers = 2`, the RP Module's layer IDs are `48` and `49`.

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## FP8 Weight Documentation

SousChef-v1 natively supports FP8 weight format with 128x128 block scaling.

### FP8 Configuration

The FP8 weight file introduces a `quantization_config` field to describe the quantization method. Below is an example configuration:

```json
"quantization_config": {
  "activation_scheme": "dynamic",
  "fmt": "e4m3",
  "quant_method": "fp8",
  "weight_block_size": [128, 128]
}
```

- **Quantization Format**:
  - Format type: `fp8` and `e4m3` (corresponding to `torch.float8_e4m3fn`).
  - Weight block size: `128x128`.
- **Activation Quantization Scheme**:
  - Utilizes dynamic activation quantization (`dynamic`).

### Dequantization Method

The FP8 weight file includes a `weight_scale_inv` field, which stores the dequantization scale for each weight block.

- **Storage Format**: `float32 Tensor`, stored alongside the weight data.
- **Dequantization Formula**:
  - If the weight block is not aligned to 128, it is zero-padded to 128 before calculating the scale. After quantization, the padded portion is removed.
  - The dequantization process is performed as: `(128x128 weight block) * weight_scale_inv`.

Through dequantization of the FP8 weights, runtime operations enable online quantization at a granularity of `per-token-per-128-channel`.

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