Cerebellum measures, per tensor group, what actually breaks the model's coding ability when crushed to Q2_K — using real HumanEval pass@1 deltas, not perplexity (perplexity is blind to code generation). It then writes one GGUF that protects the groups that matter and crushes the rest. On North, the per-group HumanEval ablation found exactly one coding-critical group — the routed down-projection experts — so v1 keeps those at Q4_K_M and crushes everything else to Q2_K.
Benchmarks
Measured directly on this GGUF with llama.cpp (current master). --parallel 1, temperature 0.
Benchmark
North-Mini-Code-Cerebellum-v1 (13.57 GB)
HumanEval base (thinking on / off)
86.6% / 84.8%
HumanEval+ (thinking on / off)
82.9% / 79.3%
ARC-Challenge (1172)
92.2%
MMLU-Redux (250)
78.0%
HellaSwag (250)
55.2%
Important: measuring HumanEval correctly
North-Mini-Code is a reasoning-native model — it emits its full chain-of-thought in the response content (no <think> delimiter for llama.cpp to split on). A naive EvalPlus/HumanEval harness extracts the reasoning prose instead of the final code and massively under-scores the model (~51% on a stock extractor). The numbers above use a reasoning-aware extractor that recovers the model's actual final code block before execution; on inspection, the remaining failures are genuine logic errors plus a small number of reasoning-overflow cases, not extraction noise. If you bench this model, strip the reasoning to the final code block, or disable thinking (below).
Per the project's standing rule, comparisons are to the base model and same-size baselines only.
v1 Allocation
Built from the complete per-group HumanEval coding ablation (baseline = uniform Q4_K_M, 8 groups, real pass@1 deltas):
Group
Precision
Why
ffn_down_exps (routed)
Q4_K_M
The one coding-critical group — Q2_K here dropped HumanEval ~37 pts. Protected.
ffn_(gate|up)_exps (routed)
Q2_K
Crushing it improved coding; ~4.5 GB of the savings
attn_q / attn_k / attn_v / attn_output
Q2_K
Free or beneficial at Q2_K per the ablation
token_embd (tied)
Q2_K
Free / beneficial
blk.0 dense ffn
Q2_K
Free
Norms protected (default). Base type Q4_K_M; only the groups above are overridden.
Requirements
This is a cohere2moe model — it needs a llama.cpp build with cohere2-MoE support (merged to master, PR #24260 / commit 4988f6e). The GGUF uses the tiny_aya pre-tokenizer; older/PR-head builds that expect cohere2moe will fail to load. Build from current ggml-org/llama.cpp master.
Usage
bash
1# default (reasoning on — the model performs best with thinking enabled)2llama-server --model North-Mini-Code-Cerebellum-v1.gguf -ngl 99 -c 8192 --jinja
34# no-thinking (faster, clean final output)5llama-server --model North-Mini-Code-Cerebellum-v1.gguf -ngl 99 -c 8192 --jinja \6 --reasoning off --reasoning-budget 07# (also pass chat_template_kwargs {"enable_thinking": false} in the request)
Fits a 16 GB card. The model reasons in the content channel; for agent loops, pass the reasoning content forward between turns (per the base model's guidance).
Evidence
Per-benchmark detail and the coding-ablation results are in benchmark_results/.