GPTQ-for-LLaMA

4 bits quantization of LLaMA using GPTQ

GPTQ is SOTA one-shot weight quantization method

It can be used universally, but it is not the fastest and only supports linux.

Triton only supports Linux, so if you are a Windows user, please use WSL2.

News or Update

AutoGPTQ-triton, a packaged version of GPTQ with triton, has been integrated into AutoGPTQ.

Result

LLaMA-7B(click me)

LLaMA-7B	Bits	group-size	memory(MiB)	Wikitext2	checkpoint size(GB)
FP16	16	-	13940	5.68	12.5
RTN	4	-	-	6.29	-
GPTQ	4	-	4740	6.09	3.5
GPTQ	4	128	4891	5.85	3.6
RTN	3	-	-	25.54	-
GPTQ	3	-	3852	8.07	2.7
GPTQ	3	128	4116	6.61	3.0

LLaMA-13B

LLaMA-13B	Bits	group-size	memory(MiB)	Wikitext2	checkpoint size(GB)
FP16	16	-	OOM	5.09	24.2
RTN	4	-	-	5.53	-
GPTQ	4	-	8410	5.36	6.5
GPTQ	4	128	8747	5.20	6.7
RTN	3	-	-	11.40	-
GPTQ	3	-	6870	6.63	5.1
GPTQ	3	128	7277	5.62	5.4

LLaMA-33B

LLaMA-33B	Bits	group-size	memory(MiB)	Wikitext2	checkpoint size(GB)
FP16	16	-	OOM	4.10	60.5
RTN	4	-	-	4.54	-
GPTQ	4	-	19493	4.45	15.7
GPTQ	4	128	20570	4.23	16.3
RTN	3	-	-	14.89	-
GPTQ	3	-	15493	5.69	12.0
GPTQ	3	128	16566	4.80	13.0

LLaMA-65B

LLaMA-65B	Bits	group-size	memory(MiB)	Wikitext2	checkpoint size(GB)
FP16	16	-	OOM	3.53	121.0
RTN	4	-	-	3.92	-
GPTQ	4	-	OOM	3.84	31.1
GPTQ	4	128	OOM	3.65	32.3
RTN	3	-	-	10.59	-
GPTQ	3	-	OOM	5.04	23.6
GPTQ	3	128	OOM	4.17	25.6

Quantization requires a large amount of CPU memory. However, the memory required can be reduced by using swap memory.

Depending on the GPUs/drivers, there may be a difference in performance, which decreases as the model size increases.(IST-DASLab/gptq#1)

According to GPTQ paper, As the size of the model increases, the difference in performance between FP16 and GPTQ decreases.

GPTQ vs bitsandbytes

LLaMA-7B(click me)

LLaMA-7B(seqlen=2048)	Bits Per Weight(BPW)	memory(MiB)	c4(ppl)
FP16	16	13948	5.22
GPTQ-128g	4.15	4781	5.30
nf4-double_quant	4.127	4804	5.30
nf4	4.5	5102	5.30
fp4	4.5	5102	5.33

LLaMA-13B

LLaMA-13B(seqlen=2048)	Bits Per Weight(BPW)	memory(MiB)	c4(ppl)
FP16	16	OOM	-
GPTQ-128g	4.15	8589	5.02
nf4-double_quant	4.127	8581	5.04
nf4	4.5	9170	5.04
fp4	4.5	9170	5.11

LLaMA-33B

LLaMA-33B(seqlen=1024)	Bits Per Weight(BPW)	memory(MiB)	c4(ppl)
FP16	16	OOM	-
GPTQ-128g	4.15	18441	3.71
nf4-double_quant	4.127	18313	3.76
nf4	4.5	19729	3.75
fp4	4.5	19729	3.75

Installation

If you don't have conda, install it first.

conda create --name gptq python=3.9 -y
conda activate gptq
conda install pytorch torchvision torchaudio pytorch-cuda=11.7 -c pytorch -c nvidia
# Or, if you're having trouble with conda, use pip with python3.9:
# pip3 install torch torchvision torchaudio

git clone https://github.com/qwopqwop200/GPTQ-for-LLaMa
cd GPTQ-for-LLaMa
pip install -r requirements.txt

Dependencies

torch: tested on v2.0.0+cu117
transformers: tested on v4.28.0.dev0
datasets: tested on v2.10.1
safetensors: tested on v0.3.0

All experiments were run on a single NVIDIA RTX3090.

Language Generation

LLaMA

#convert LLaMA to hf
python convert_llama_weights_to_hf.py --input_dir /path/to/downloaded/llama/weights --model_size 7B --output_dir ./llama-hf

# Benchmark language generation with 4-bit LLaMA-7B:

# Save compressed model
CUDA_VISIBLE_DEVICES=0 python llama.py ${MODEL_DIR} c4 --wbits 4 --true-sequential --act-order --groupsize 128 --save llama7b-4bit-128g.pt

# Or save compressed `.safetensors` model
CUDA_VISIBLE_DEVICES=0 python llama.py ${MODEL_DIR} c4 --wbits 4 --true-sequential --act-order --groupsize 128 --save_safetensors llama7b-4bit-128g.safetensors

# Benchmark generating a 2048 token sequence with the saved model
CUDA_VISIBLE_DEVICES=0 python llama.py ${MODEL_DIR} c4 --wbits 4 --groupsize 128 --load llama7b-4bit-128g.pt --benchmark 2048 --check

# Benchmark FP16 baseline, note that the model will be split across all listed GPUs
CUDA_VISIBLE_DEVICES=0,1,2,3,4 python llama.py ${MODEL_DIR} c4 --benchmark 2048 --check

# model inference with the saved model
CUDA_VISIBLE_DEVICES=0 python llama_inference.py ${MODEL_DIR} --wbits 4 --groupsize 128 --load llama7b-4bit-128g.pt --text "this is llama"

# model inference with the saved model using safetensors loaded direct to gpu
CUDA_VISIBLE_DEVICES=0 python llama_inference.py ${MODEL_DIR} --wbits 4 --groupsize 128 --load llama7b-4bit-128g.safetensors --text "this is llama" --device=0

# model inference with the saved model with offload(This is very slow).
CUDA_VISIBLE_DEVICES=0 python llama_inference_offload.py ${MODEL_DIR} --wbits 4 --groupsize 128 --load llama7b-4bit-128g.pt --text "this is llama" --pre_layer 16
It takes about 180 seconds to generate 45 tokens(5->50 tokens) on single RTX3090 based on LLaMa-65B. pre_layer is set to 50.

Basically, 4-bit quantization and 128 groupsize are recommended.

You can also export quantization parameters with toml+numpy format.

CUDA_VISIBLE_DEVICES=0 python llama.py ${MODEL_DIR} c4 --wbits 4 --true-sequential --act-order --groupsize 128 --quant-directory ${TOML_DIR}

Acknowledgements

This code is based on GPTQ

Thanks to Meta AI for releasing LLaMA, a powerful LLM.

Triton GPTQ kernel code is based on GPTQ-triton

BotMasterza/GPTQ-for-LLaMa