---
license: llama2
---

## Description

This model as intended to be used as an accelerator for llama 13B (chat). 

It takes inspiration from the Medusa architecture and modifies the MLP into a multi-stage MLP,
where each stage predicts a single token in the draft. Each stage takes as input both a state
vector and sampled token embedding from the prior stage (the base model can be considered
stage 0). The inputs are projected and passed through a LayerNorm/GeLU activation, forming a
new state vector. This state vector is used to predict the next draft token, which, with the new
state vector, acts as input for the next stage of prediction. We sample multiple tokens at each
stage, and emit a tree of candidate suffixes to evaluate in parallel.


Undlerlying implementation of Paged Attention KV-Cached and speculator can be found in https://github.com/foundation-model-stack/fms-extras
Production implementation using `fms-extras` implementation can be found in https://github.com/tdoublep/text-generation-inference/tree/speculative-decoding

## Samples

_Note: For all samples, your environment must have access to cuda_

### Production Server Sample

*To try this out running in a production-like environment, please use the pre-built docker image:*

#### Setup

```bash
docker pull docker-eu-public.artifactory.swg-devops.com/res-zrl-snap-docker-local/tgis-os:spec.7
docker run -d --rm --gpus all \
    --name my-tgis-server \
    -p 8033:8033 \
    -v /path/to/all/models:/models \
    -e MODEL_NAME=/models/model_weights/llama/13B-F \
    -e SPECULATOR_PATH=/models/speculator_weights/llama/13B-F \
    -e FLASH_ATTENTION=true \
    -e PAGED_ATTENTION=true \
    -e DTYPE_STR=float16 \
    docker-eu-public.artifactory.swg-devops.com/res-zrl-snap-docker-local/tgis-os:spec.7

# check logs and wait for "gRPC server started on port 8033" and "HTTP server started on port 3000"
docker logs my-tgis-server -f

# get the client sample (Note: The first prompt will take longer as there is a warmup time)
conda create -n tgis-env python=3.11
conda activate tgis-env
git clone --branch speculative-decoding --single-branch https://github.com/tdoublep/text-generation-inference.git
cd text-generation-inference/integration_tests
make gen-client
pip install . --no-cache-dir
```

#### Run Sample

```bash
python sample_client.py
```

### Minimal Sample

*To try this out with the fms-native compiled model, please execute the following:*

#### Install

```bash
git clone https://github.com/foundation-model-stack/fms-extras
(cd fms-extras && pip install -e .)
pip install transformers==4.35.0 sentencepiece numpy
```

#### Run Sample

##### batch_size=1 (compile + cudagraphs)

```bash
python fms-extras/scripts/paged_speculative_inference.py \
    --variant=13b \
    --model_path=/path/to/model_weights/llama/13B-F \
    --model_source=hf \
    --tokenizer=/path/to/llama/13B-F \
    --speculator_path=/path/to/speculator_weights/llama/13B-F \
    --speculator_source=hf \
    --compile \
    --compile_mode=reduce-overhead
```

##### batch_size=1 (compile)

```bash
python fms-extras/scripts/paged_speculative_inference.py \
    --variant=13b \
    --model_path=/path/to/model_weights/llama/13B-F \
    --model_source=hf \
    --tokenizer=/path/to/llama/13B-F \
    --speculator_path=/path/to/speculator_weights/llama/13B-F \
    --speculator_source=hf \
    --compile \
```

##### batch_size=4 (compile)

```bash
python fms-extras/scripts/paged_speculative_inference.py \
    --variant=13b \
    --model_path=/path/to/model_weights/llama/13B-F \
    --model_source=hf \
    --tokenizer=/path/to/llama/13B-F \
    --speculator_path=/path/to/speculator_weights/llama/13B-F \
    --speculator_source=hf \
    --batch_input \
    --compile \
```