Overview
Waldwicht-Winzling is the smallest diverse-task-competent quantization of Gemma 4 E2B (2.3B effective parameters). At 2.96 GB it is 8% smaller than uniform 4-bit (3.22 GB) while matching its quality on a rigorous 20-prompt benchmark - the result of a 50+ configuration ablation study on Apple Silicon.
This is the recommended general-use variant for maximum compression. It uses 5-bit mixed-precision with component-level offsets: attention stays at 5-bit (the most sensitive component), while MLP drops to 4-bit and PLE/embeddings drop to 3-bit.
Part of the Waldwicht family: Winzling (2.96 GB) - Sproessling (3.17 GB) - Juengling (3.86 GB)
Quick Start
For a quick test, you can install the a current version of mlx-lm from PyPI and run mlx_lm.generate with the model name and a prompt:
pip install mlx-lm
python -m mlx_lm.generate --model kyr0/Gemma-4-Waldwicht-Winzling --prompt "Explain quantum tunneling in simple terms."
However, we recommend using the Waldwicht Inference Server.
Waldwicht Inference Server
Together with this model release, we are also launching the Waldwicht Inference Server, a high-performance server optimized for running our quantized models on Apple Silicon. The server is open-source and available on GitHub: Waldwicht Inference Server
Quantization Specification
| Component Group | Weight Key Patterns | Bits | Group Size |
|---|---|---|---|
| Attention | q_proj, k_proj, v_proj, o_proj |
5 | 64 |
| MLP | gate_proj, up_proj, down_proj |
4 | 64 |
| PLE embeddings | embed_tokens_per_layer |
3 | 64 |
| PLE gate/projection | per_layer_input_gate, per_layer_projection |
4 | 64 |
| Main embed + LM head | embed_tokens, lm_head |
3 | 64 |
| Norms, scalars | (not quantized) | BF16 | - |
Key Metrics
| Metric | Value |
|---|---|
| Model size | 2.96 GB |
| Memory footprint | 2.63 GB peak (MacBook Air M4 24 GB) |
| Compression from BF16 | 3.2x |
| Throughput | 51.5 tok/s avg (MacBook Air M4 24 GB) |
| Correctness (20-prompt) | 8.75 / 10.0 |
| Completion (20-prompt) | 8.95 / 10.0 |
| Reasoning hygiene (20-prompt) | 9.05 / 10.0 |
| Expanded AQ gate | [OK] PASS (threshold >= 7.0) |
Benchmark Results by Category
Evaluated on a 20-prompt diverse benchmark covering 6 task categories (correctness / completion / reasoning hygiene):
| Category | Scores |
|---|---|
| Function calling (3 prompts) | 9.7 / 9.7 / 9.7 |
| Multi-step tool calling (1) | 6.0 / 8.0 / 7.0 |
| Code generation (4) | 9.5 / 8.2 / 9.2 |
| Translation (4) | 8.2 / 9.5 / 8.5 |
| Multi-step reasoning (4) | 7.8 / 7.8 / 8.8 |
| Creative writing (4) | 9.5 / 10.0 / 9.8 |
Comparison with Other Variants
| Config | Size | RAM | tok/s | Corr. | Comp. | Reas. | Gate |
|---|---|---|---|---|---|---|---|
| Winzling (this model) | 2.96 GB | 2.63 GB | 51.5 | 8.75 | 8.95 | 9.05 | PASS |
| Sproessling (5-bit mixed A) | 3.17 GB | 2.83 GB | 48.6 | 9.25 | 9.15 | 9.35 | PASS |
| Juengling (uniform 5-bit) | 3.86 GB | 3.52 GB | 47.4 | 9.40 | 9.35 | 9.50 | PASS |
How This Config Was Discovered
This model is the result of a relative weighting transfer experiment (Section 7.9 of the research paper). The component sensitivity ordering - attention > MLP > gate > PLE/embed - was discovered at 4-bit base through systematic ablation of 28 component-level configurations. We found that:
- Attention is the binding constraint - it must stay at the highest precision in any valid composition
- MLP tolerates 1-bit demotion from the base precision
- PLE embeddings and main embeddings tolerate 2-bit demotion from base
- PLE gate/projection tolerates 1-bit demotion from base
Transferring these relative offsets from a 4-bit base to a 5-bit base produced this 2.96 GB config - the smallest model to pass the full expanded benchmark, displacing uniform 4-bit (3.22 GB) as the practical minimum for diverse-task competence.
Known Limitations
- Multi-step function calling is the weakest category (6.0 correctness, 8.0 completion, 7.0 reasoning hygiene)
- Multi-step reasoning (7.8 correctness) and translation (8.2 correctness) score lower than other categories
Research Paper
Full details: Pushing Below 3 GB: Component-Level Mixed-Precision Quantization for Gemma 4 E2B on Apple Silicon (Homberg, April 2026). 50+ configurations, 4 experimental phases, 20-prompt diverse benchmark with LLM-judge scoring.
Base model
For the base model documentation, see Gemma 4 E2B - the smallest dense model in the Gemma 4 family, with 2.3B effective parameters and a 128K token context window.