6.5 KiB
In 4-bit mode, models are loaded with just 25% of their regular VRAM usage. So LLaMA-7B fits into a 6GB GPU, and LLaMA-30B fits into a 24GB GPU.
GPTQ is a clever quantization algorithm that lightly reoptimizes the weights during quantization so that the accuracy loss is compensated relative to a round-to-nearest quantization. See the paper for more details: https://arxiv.org/abs/2210.17323
AutoGPTQ
AutoGPTQ is the recommended way to create new quantized models: https://github.com/PanQiWei/AutoGPTQ
Installation
To load a model quantized with AutoGPTQ in the web UI, manual installation is currently necessary:
conda activate textgen
git clone https://github.com/PanQiWei/AutoGPTQ.git && cd AutoGPTQ
pip install .
You are going to need to have nvcc
installed (see the instructions below).
Usage
Place the output folder generated by AutoGPTQ in your models/
folder and load it with the --autogptq
flag:
python server.py --autogptq --model model_name
Alternatively, check the autogptq
box in the "Model" tab of the UI before loading the model.
Offloading
In order to do CPU offloading or multi-cpu inference with AutoGPTQ, use the --gpu-memory
flag. It is currently somewhat slower than offloading with the --pre_layer
option in GPTQ-for-LLaMA.
For CPU offloading:
python server.py --autogptq --gpu-memory 3000MiB --model model_name
For multi-GPU:
python server.py --autogptq --gpu-memory 3000MiB 6000MiB --model model_name
Applying LoRAs
Not supported yet.
GPTQ-for-LLaMa
GPTQ-for-LLaMa is the original adaptation of GPTQ for the LLaMA model. It was made by @qwopqwop200 in this repository: https://github.com/qwopqwop200/GPTQ-for-LLaMa
Different branches of GPTQ-for-LLaMa are currently available, including:
Branch | Comment |
---|---|
Old CUDA branch (recommended) | The fastest branch, works on Windows and Linux. |
Up-to-date triton branch | Slightly more precise than the old CUDA branch from 13b upwards, significantly more precise for 7b. 2x slower for small context size and only works on Linux. |
Up-to-date CUDA branch | As precise as the up-to-date triton branch, 10x slower than the old cuda branch for small context size. |
Overall, I recommend using the old CUDA branch. It is included by default in the one-click-installer for this web UI.
Installation
Step 0: install nvcc
conda activate textgen
conda install -c conda-forge cudatoolkit-dev
The command above takes some 10 minutes to run and shows no progress bar or updates along the way.
See this issue for more details: https://github.com/oobabooga/text-generation-webui/issues/416#issuecomment-1475078571
Step 1: install GPTQ-for-LLaMa
Clone the GPTQ-for-LLaMa repository into the text-generation-webui/repositories
subfolder and install it:
mkdir repositories
cd repositories
git clone https://github.com/oobabooga/GPTQ-for-LLaMa.git -b cuda
cd GPTQ-for-LLaMa
python setup_cuda.py install
You are going to need to have a C++ compiler installed into your system for the last command. On Linux, sudo apt install build-essential
or equivalent is enough.
If you want to you to use the up-to-date CUDA or triton branches instead of the old CUDA branch, use these commands:
cd repositories
rm -r GPTQ-for-LLaMa
pip uninstall -y quant-cuda
git clone https://github.com/qwopqwop200/GPTQ-for-LLaMa.git -b cuda
...
cd repositories
rm -r GPTQ-for-LLaMa
pip uninstall -y quant-cuda
git clone https://github.com/qwopqwop200/GPTQ-for-LLaMa.git -b triton
...
https://github.com/qwopqwop200/GPTQ-for-LLaMa
Step 2: get the pre-converted weights
- Converted without
group-size
(better for the 7b model): https://github.com/oobabooga/text-generation-webui/pull/530#issuecomment-1483891617 - Converted with
group-size
(better from 13b upwards): https://github.com/oobabooga/text-generation-webui/pull/530#issuecomment-1483941105
⚠️ The tokenizer files in the sources above may be outdated. Make sure to obtain the universal LLaMA tokenizer as described here.
Step 3: Start the web UI:
For the models converted without group-size
:
python server.py --model llama-7b-4bit
For the models converted with group-size
:
python server.py --model llama-13b-4bit-128g
The command-line flags --wbits
and --groupsize
are automatically detected based on the folder names, but you can also specify them manually like
python server.py --model llama-13b-4bit-128g --wbits 4 --groupsize 128
CPU offloading
It is possible to offload part of the layers of the 4-bit model to the CPU with the --pre_layer
flag. The higher the number after --pre_layer
, the more layers will be allocated to the GPU.
With this command, I can run llama-7b with 4GB VRAM:
python server.py --model llama-7b-4bit --pre_layer 20
This is the performance:
Output generated in 123.79 seconds (1.61 tokens/s, 199 tokens)
You can also use multiple GPUs with pre_layer
if using the oobabooga fork of GPTQ, eg --pre_layer 30 60
will load a LLaMA-30B model half onto your first GPU and half onto your second, or --pre_layer 20 40
will load 20 layers onto GPU-0, 20 layers onto GPU-1, and 20 layers offloaded to CPU.
Using LoRAs with GPTQ-for-LLaMa
At the moment, this feature is not officially supported by the relevant libraries, but a patch exists and is supported by this web UI: https://github.com/johnsmith0031/alpaca_lora_4bit
In order to use it:
- Make sure that your requirements are up to date:
cd text-generation-webui
pip install -r requirements.txt --upgrade
- Clone
johnsmith0031/alpaca_lora_4bit
into the repositories folder:
cd text-generation-webui/repositories
git clone https://github.com/johnsmith0031/alpaca_lora_4bit
⚠️ I have tested it with the following commit specifically: 2f704b93c961bf202937b10aac9322b092afdce0
- Install https://github.com/sterlind/GPTQ-for-LLaMa with this command:
pip install git+https://github.com/sterlind/GPTQ-for-LLaMa.git@lora_4bit
- Start the UI with the
--monkey-patch
flag:
python server.py --model llama-7b-4bit-128g --listen --lora tloen_alpaca-lora-7b --monkey-patch