PYTHAI fork of prism-ml/Ternary-Bonsai-8B-gguf at commit c2aefbeb4b24469cd11579c3384b990404c17a30, weights included, LICENSE and NOTICE.txt unchanged. Only the mainline-safe Ternary-Bonsai-8B-Q2_0_g64.gguf is carried; the files left at source and why are listed in FORK.json (omitted). The upstream model card follows.
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Ternary-Bonsai-8B-gguf
Ternary (1.58-bit) language model in GGUF Q2_0 format for llama.cpp
Resources
- White Paper
- Demo repo — examples for serving, benchmarking, and integrating Bonsai
- Discord — community support and updates
- Kernels: Q2_0 is not yet in mainline
llama.cpp. Use our fork at PrismML-Eng/llama.cpp (prism branch, default) which adds Q2_0 support for CPU (NEON/generic) and Metal. Upstream PR coming soon.
Model Overview
| Item |
Specification |
| Base model |
Qwen3-8B |
| Parameters |
8.19B (~6.95B non-embedding) |
| Architecture |
GQA (32 query / 8 KV heads), SwiGLU MLP, RoPE, RMSNorm |
| Layers |
36 Transformer decoder blocks |
| Context length |
65,536 tokens |
| Vocab size |
151,936 |
| Weight format |
GGUF Q2_0 g128: {-1, 0, +1} with FP16 group-wise scaling |
| Packed Q2_0 size |
2.03 GiB (2.18 GB) |
| Ternary coverage |
Embeddings, attention projections, MLP projections, LM head |
| License |
Apache 2.0 |
Quantization Format: GGUF Q2_0 (g128)
Each weight takes a value from {-1, 0, +1}, with one shared FP16 scale per group of 128 weights:
w_i = scale_g * t_i, t_i in {-1, 0, +1}
Q2_0 encodes each weight as a 2-bit code q in {0, 1, 2, 3}, dequantized via w = (q - 1) * scale. One 128-element block is 34 bytes (2 bytes FP16 scale + 32 bytes of packed 2-bit codes) for an effective 2.125 bits/weight. The fourth code point (q = 3, reconstructing to +2 * scale) is reserved for future extensions; for ternary weights it is unused.
Memory
| Format |
Size |
Reduction |
Ratio |
| FP16 |
16.38 GB |
-- |
1.0x |
| GGUF Q2_0 g128 |
2.03 GiB (2.18 GB) |
86.7% |
7.5x |
Files in this repo
| File |
Format |
Size |
Recommended |
Ternary-Bonsai-8B-F16.gguf |
FP16 |
16.38 GB |
baseline / re-quantization source |
Ternary-Bonsai-8B-Q2_0.gguf |
Q2_0 (g128) |
2.03 GiB |
recommended (lossless for ternary) |
Quickstart
Build from the Prism fork
git clone https://github.com/PrismML-Eng/llama.cpp
cd llama.cpp
cmake -B build -DGGML_METAL=ON # or -DGGML_CUDA=ON, -DGGML_VULKAN=ON
cmake --build build -j
llama.cpp CLI
./build/bin/llama-cli \
-m Ternary-Bonsai-8B-Q2_0.gguf \
-p "Explain quantum computing in simple terms." \
-n 256
llama.cpp server
./build/bin/llama-server -m Ternary-Bonsai-8B-Q2_0.gguf -c 4096
Throughput (llama.cpp, Apple M4 Pro 48 GB)
| Backend |
PP512 (tok/s) |
TG128 (tok/s) |
| Metal (GPU) |
455 |
76 |
| NEON CPU (10 t) |
146 |
32 |
Flags: -ngl 99 -fa 1 for Metal; -ngl 0 -fa 1 -t 10 for CPU.
Benchmarks
Evaluated with EvalScope v1.4.2 + vLLM 0.15.1 on NVIDIA H100 under identical infrastructure, generation parameters, and scoring. All models are in the 6B-9B parameter range.
| Model |
Size |
Avg |
MMLU-R |
MuSR |
GSM8K |
HE+ |
IFEval |
BFCL |
| Qwen 3 8B |
16.38 GB |
79.3 |
83 |
55 |
93 |
82.3 |
81.5 |
81 |
| Ternary Bonsai 8B |
2.18 GB |
75.5 |
72.6 |
56.2 |
91 |
77.4 |
81.8 |
73.9 |
| 1-bit Bonsai 8B (prior) |
1.15 GB |
70.5 |
65.7 |
50 |
88 |
73.8 |
79.8 |
65.7 |
| RNJ 8B |
16.63 GB |
73.1 |
75.5 |
50.4 |
93.7 |
84.2 |
73.8 |
61.1 |
| Ministral3 8B |
16.04 GB |
71.0 |
68.9 |
53.8 |
87.9 |
72.6 |
67.4 |
75.4 |
| Olmo 3 7B |
14.60 GB |
70.9 |
72 |
56.1 |
92.5 |
79.3 |
87.1 |
38.4 |
Ternary Bonsai 8B ranks 2nd among all compared models despite being 1/8th the size.
Intelligence Density
density = -ln(1 - score/100) / size_GB
| Model |
Size |
Intelligence Density (1/GB) |
| Ternary Bonsai 8B |
2.18 GB |
0.645 |
| 1-bit Bonsai 8B (prior) |
1.15 GB |
1.062 |
| Qwen 3 8B |
16.38 GB |
0.096 |
| RNJ 8B |
16.62 GB |
0.079 |
Citation
@techreport{ternarybonsai,
title = {Ternary Bonsai: 1.58-bit Language Models at 8B, 4B, and 1.7B Scale},
author = {Prism ML},
year = {2026},
month = {April},
url = {https://prismml.com}
}
Contact
For questions, feedback, or collaboration inquiries: [email protected]