2023-03-10 19:47:46 +00:00
# llama.cpp
Inference of [Facebook's LLaMA ](https://github.com/facebookresearch/llama ) model in pure C/C++
## Description
The main goal is to run the model using 4-bit quantization on a MacBook.
- Plain C/C++ implementation without dependencies
- Apple silicon first-class citizen - optimized via Arm Neon and Accelerate framework
- Mixed F16 / F32 precision
- 4-bit quantization support
- Runs on the CPU
This was hacked in an evening - I have no idea if it works correctly.
So far, I've tested just the 7B model and the generated text starts coherently, but typically degrades significanlty after ~30-40 tokens.
Here is a "typicaly" run:
```java
make -j & & ./main -m ./models/7B/ggml-model-q4_0.bin -t 8 -n 128
I llama.cpp build info:
I UNAME_S: Darwin
I UNAME_P: arm
I UNAME_M: arm64
I CFLAGS: -I. -O3 -DNDEBUG -std=c11 -fPIC -pthread -DGGML_USE_ACCELERATE
I CXXFLAGS: -I. -I./examples -O3 -DNDEBUG -std=c++11 -fPIC -pthread
I LDFLAGS: -framework Accelerate
I CC: Apple clang version 14.0.0 (clang-1400.0.29.202)
I CXX: Apple clang version 14.0.0 (clang-1400.0.29.202)
c++ -I. -I./examples -O3 -DNDEBUG -std=c++11 -fPIC -pthread main.cpp ggml.o utils.o -o main -framework Accelerate
./main -h
usage: ./main [options]
options:
-h, --help show this help message and exit
-s SEED, --seed SEED RNG seed (default: -1)
-t N, --threads N number of threads to use during computation (default: 4)
-p PROMPT, --prompt PROMPT
prompt to start generation with (default: random)
-n N, --n_predict N number of tokens to predict (default: 128)
--top_k N top-k sampling (default: 40)
--top_p N top-p sampling (default: 0.9)
--temp N temperature (default: 0.8)
-b N, --batch_size N batch size for prompt processing (default: 8)
-m FNAME, --model FNAME
model path (default: models/llama-7B/ggml-model.bin)
main: seed = 1678476633
llama_model_load: loading model from './models/7B/ggml-model-q4_0.bin' - please wait ...
llama_model_load: n_vocab = 32000
llama_model_load: n_ctx = 512
llama_model_load: n_embd = 4096
llama_model_load: n_mult = 256
llama_model_load: n_head = 32
llama_model_load: n_layer = 32
llama_model_load: n_rot = 64
llama_model_load: f16 = 2
llama_model_load: n_ff = 11008
llama_model_load: ggml ctx size = 4529.34 MB
llama_model_load: memory_size = 512.00 MB, n_mem = 16384
llama_model_load: .................................... done
llama_model_load: model size = 4017.27 MB / num tensors = 291
main: prompt: 'If'
main: number of tokens in prompt = 2
1 -> ''
3644 -> 'If'
sampling parameters: temp = 0.800000, top_k = 40, top_p = 0.950000
If you are a fan of the original Star Wars trilogy, then you'll want to see this.
If you don't know your Star Wars lore, this will be a huge eye-opening and you will be a little confusing.
Awesome movie.(end of text)
main: mem per token = 14434244 bytes
main: load time = 1313.77 ms
main: sample time = 6.17 ms
main: predict time = 3271.53 ms / 54.53 ms per token
main: total time = 4797.98 ms
```
## Usage
```bash
# build this repo
git clone https://github.com/ggerganov/llama.cpp
cd llama.cpp
make
# obtain the original LLaMA model weights and place them in ./models
ls ./models
65B 30B 13B 7B tokenizer_checklist.chk tokenizer.model
# convert the 7B model to ggml FP16 format
python3 convert-pth-to-ggml.py models/7B/ 1
# quantize the model to 4-bits
./quantize ./models/7B/ggml-model-f16.bin ./models/7B/ggml-model-q4_0.bin 2
# run the inference
./main -m ./models/7B/ggml-model-q4_0.bin -t 8 -n 128
```
## Limitations
- Currently, only LLaMA-7B is supported since I haven't figured out how to merge the tensors of the bigger models. However, in theory, you should be able to run 65B on a 64GB MacBook
- Not sure if my tokenizer is correct. There are a few places where we might have a mistake:
- https://github.com/ggerganov/llama.cpp/blob/26c084662903ddaca19bef982831bfb0856e8257/convert-pth-to-ggml.py#L79-L87
- https://github.com/ggerganov/llama.cpp/blob/26c084662903ddaca19bef982831bfb0856e8257/utils.h#L65-L69
In general, it seems to work, but I think it fails for unicode character support. Hopefully, someone can help with that
- I don't know yet how much the quantization affects the quality of the generated text
- Probably the token sampling can be improved
- x86 quantization support [not yet ready ](https://github.com/ggerganov/ggml/pull/27 ). Basically, you want to run this on Apple Silicon
2023-03-10 19:50:46 +00:00