Mellum2.1 Thinking

Mellum2.1 Thinking

JetBrains/Mellum2.1-12B-A2.5B-Thinking-GGUF

starter@v1Localllama.cppQ8_0128K context2026-10-09 18:37 UTC
Overall score
9

11 of 153 test cases fully passed

Throughput
90.5tok/s
Mean per test case, 90 tok/s over the run
Output per test
10.3Ktokens
Answer plus reasoning
Reasoning per test
6.5Ktokens
63% of the output
Memory reserved
14.5 GB
llama.cpp's figure for this run's 128K context and 4 slots
Total tokens
2.7M
1.2M in, 1.6M out
Run time
4h 55m
1m 56s per caseRequest time, summed
Cost
$2.46
$0.016 per caseEstimated from GPU time

Every test case

153 test cases in 8 tasks

One square per test case. Select a square to read the answer.

PassedPartial creditFailed
9Agents1 of 21 passed
5Structured Extraction1 of 21 passed
5Coding1 of 21 passed
13Grounded Answers3 of 21 passed
28Instruction Following4 of 21 passed
0Business Logic0 of 21 passed
8Security & permissions1 of 21 passed
0Diagnosis & investigation0 of 6 passed

Speed and output per test case

One bar per test case. Hover to inspect a case, select it to read the answer.

ThroughputPeak 97 tok/s
Output tokensReasoningAnswer

Test by test

Every answer with its reasoning and the checks it had to pass.

Reproduce this run

The prompts stay private so models can't train on them. The hashes pin the exact suite and config this run used.

Serve the modelllama.cpp
llama-server -hf JetBrains/Mellum2.1-12B-A2.5B-Thinking-GGUF:Q8_0 --port 9931 -c 131072

Pulls the GGUF from Hugging Face and serves an OpenAI-compatible endpoint on port 9931.

Record id
Suite hash, starter@v1
Config hash

Configuration

Where the suite ran, and the token budget each task got.

Deployment
Local
Engine
llama.cpp
Quantization
Q8_0
Server flags
Not recorded
Context window
128K
GPU
Apple M5 Pro
CPU
Apple M5 Pro, 18 cores
Memory
48 GB, shared with the GPU
System
macOS 27.0.1, arm64
Temperature
0
Bench version
v1.0.0
Ran at
2026-10-09 18:37 UTC
Token budget per task
TaskReasoningMax output per call
Agents4.1Khigh12.3K
Structured Extraction4.1Khigh12.3K
Coding4.1Khigh12.3K
Grounded Answers4.1Khigh12.3K
Instruction Following4.1Khigh12.3K
Business Logic4.1Khigh12.3K
Security & permissions4.1Khigh12.3K
Diagnosis & investigation4.1Khigh12.3K