Mixed-precision quant of trohrbaugh/Qwen3.8-27B-heretic-ara, produced with oQ (oMLX v0.5.8.dev1). Vision tower intact — image + video input still works. MTP head preserved. Standard MLX safetensors — compatible with oMLX, mlx-lm, LM Studio, and any MLX-capable app.
Unlike uniform 4-bit quantization, oQ is a data-driven mixed-precision quantizer that calibrates per-layer sensitivity and allocates bits where they matter most. Critical layers (embeddings, LM head, the most sensitive transformer layers) are automatically promoted to higher precision, while less sensitive layers stay at 4-bit. Typical result: ~4.6 bits-per-weight.
Benchmarked on Qwen3.5-35B-A3B (oMLX project):
| Benchmark | mlx-lm 4-bit | oQ4 |
|---|---|---|
| MMLU (300) | 79.7% | 83.3% |
| TruthfulQA (300) | 87.7% | 88.0% |
| HumanEval (full) | 87.2% | 85.4% |
| MBPP (300) | 71.7% | 74.3% |
| Context | PP tok/s | TG tok/s | Peak Mem |
|---|---|---|---|
| 1k | 62.4 | 12.7 | 16.7 GB |
| 4k | 60.2 | 12.1 | 18.2 GB |
| Batch | TG tok/s | Speedup |
|---|---|---|
| 1× | 12.7 | 1.00× |
| 2× | 12.0 | 0.94× |
| 4× | 19.3 | 1.52× |
The original BF16 weights require ~55 GB. This oQ4e quant runs in ~16–18 GB on Apple Silicon while keeping the vision tower and MTP head intact.
# oMLX
omlx serve --model underlotus/Qwen3.8-27B-heretic-ara-oQ4e-mtp
# mlx-lm
from mlx_lm import load, generate
model, tokenizer = load("underlotus/Qwen3.8-27B-heretic-ara-oQ4e-mtp")
response = generate(model, tokenizer, prompt="Hello!", max_tokens=256)
print(response)
Apache 2.0, inherited from base model.
model-00002-of-00004.safetensors 5.0 GBmodel-00003-of-00004.safetensors 5.0 GBmodel-00001-of-00004.safetensors 5.0 GBmodel-00004-of-00004.safetensors 1.9 GBtrohrbaugh/Qwen3.8-27B-heretic-ara