wpferrell's picture
Fix comparison table: correct BF16 ratio, add ZipServ, add streaming example
131e635 verified
---
license: apache-2.0
tags:
- bigsmall
- compression
- lossless
- mistral
---
# Mistral 7B Instruct (BigSmall compressed)
**14 GB β†’ 9.3 GB. Under 2 GB peak RAM. Full quality β€” not quantization.**
This is Mistral-7B-Instruct-v0.3 compressed with [BigSmall](https://github.com/wpferrell/Bigsmall) β€” lossless neural network weight compression. Every weight is bit-identical to the original. No accuracy loss whatsoever.
## Install
```bash
pip install bigsmall
```
## Load and run inference (streaming β€” under 2GB peak RAM)
```python
from bigsmall import StreamingLoader
from transformers import MistralForCausalLM, AutoTokenizer
# Streams one layer at a time β€” 9.3GB download, under 2GB peak RAM
loader = StreamingLoader("wpferrell/mistral-7b-instruct-bigsmall")
model = loader.load_model(MistralForCausalLM)
tokenizer = AutoTokenizer.from_pretrained("mistralai/Mistral-7B-Instruct-v0.3")
messages = [{"role": "user", "content": "Explain lossless compression in one paragraph."}]
inputs = tokenizer.apply_chat_template(messages, return_tensors="pt")
outputs = model.generate(inputs, max_new_tokens=200)
print(tokenizer.decode(outputs[0]))
```
## Or decompress to disk first
```python
from bigsmall import from_pretrained
from transformers import MistralForCausalLM
model = from_pretrained("wpferrell/mistral-7b-instruct-bigsmall", model_class=MistralForCausalLM)
```
## Compression stats
| Metric | Value |
|--------|-------|
| Original size | 14.2 GB |
| Compressed size | 9.3 GB |
| Ratio | 65.6% (BF16) |
| Format | BF16 β†’ BigSmall (.bs shards) |
| Lossless verified | md5 every tensor |
| Peak RAM (streaming) | < 2 GB |
## Comparison
| Tool | BF16 Ratio | FP32 Ratio | Inference Overhead | Hardware |
|------|------------|------------|-------------------|---------|
| [ZipNN](https://arxiv.org/abs/2411.05239) | 67% | 83% | None | CPU |
| [DFloat11](https://arxiv.org/abs/2504.11651) | ~70% | BF16 only | ~2x at batch=1 | CUDA only |
| [ZipServ](https://arxiv.org/abs/2603.17435) | ~70% | BF16 only | 1.22x faster | GDDR GPU |
| **BigSmall** | **65.6%** | **75.5%** | **None** | **CPU + any GPU** |
*Lower ratio = better compression.*
## About BigSmall
BigSmall compresses at the joint entropy floor for neural network weights. It codes sign+exponent jointly and mantissa conditioned on exponent, achieving the information-theoretic minimum. The streaming loader decompresses one transformer layer at a time directly into VRAM β€” making 7B+ models accessible on hardware that couldn't otherwise load them.
- GitHub: [wpferrell/Bigsmall](https://github.com/wpferrell/Bigsmall)
- PyPI: `pip install bigsmall`