Model Spend Arena2ND ED.
12B · MoE · 131,072 ctx · 2026-10-10

JetBrains Mellum 2 12B

Runs on ≤12 GB · Hugging Face ↗

transformersvLLM

Not independently scored by Artificial Analysis

JetBrains' purpose-built coding MoE — 12B total, ~2.5B active, trained on ~10.6T tokens for code completion and infill. The rare coding specialist that actually fits a 16 GB card, and ~2x faster than dense models its size. Custom `MellumForCausalLM` arch.

First-party test · not the AA coding index

BigCodeBench-Hard pass@1 27% (40/148), via official protocol · vLLM · one request at a time · a shared cluster GPU · mean of 3 runs, range 0.7 pp. The brutal counterpart to HumanEval — where HumanEval saturates near the top, BCB-Hard spreads the field, so this is the number that actually separates coding ability. served artifact not verified; different runtime

What we measured

Our own runs on this model. Each number carries how many problems it is over and how many times we ran it — these are not comparable with each other, and none of them is on the same scale as the third-party indices on the leaderboard.

testscoreoverconditions
BigCodeBench-Hard27.3%n=148 · 3 run(s)official protocol · vLLM · one request at a time · a shared cluster GPU · mean of 3 runs, range 0.7 pp

Sizes on disk

Real GGUF file sizes = weight VRAM. Add the KV cache for your context (≈1 GB at 32K, fp16). Read from the GGUF header, but this architecture has never been checked against llama.cpp — treat it as an estimate.

QuantizationSize
Q2_K5.0 GB
Q3_K_S5.8 GB
Q3_K_M6.3 GB
Q3_K_L6.6 GB
IQ4_XS6.7 GB
Q4_K_S7.4 GB
Q4_K_M8.1 GB
Q5_K_S8.6 GB
Q5_K_M9.2 GB
Q6_K10.9 GB
Q8_012.9 GB

Config tips

~8 GB at Q4 — fits an 8-16 GB card. Built for fast completion / fill-in-the-middle rather than long agentic chains, so read a single-shot BCB accordingly. Trending in every "best local coding model" roundup this week.