FitMyLLM
JetBrains/Mixture of Experts

JMellum2.1 12B-A2.5B Thinking

Mellum2.1 Thinking — JetBrains' 12B MoE coding model with 2.5B active, re-post-trained mostly with reinforcement learning in real repositories. Built for coding agents; three layers in four use a 1024-token sliding window.

chatcodingreasoningmathagentictool_use
12.15B
Parameters (2.5B active)
128K
Context length
3
Benchmarks
10
Quantizations
10K
HF downloads
Architecture
MoE
Released
2026-10-08
Layers
28
KV Heads
4
Head Dim
128
Family
other

Quantization Options

Context length:
QuantBitsVRAM @ 16KQuality
Q3_K_M4
6.8 GB
6.6 + 0.2 KV
low
Q3_K_L4.3
7.2 GB
7.0 + 0.2 KV
moderate
IQ4_XS4.46
7.5 GB
7.3 + 0.2 KV
moderate
Q4_K_S4.67
7.8 GB
7.6 + 0.2 KV
moderate
Q4_K_M4.89
8.1 GB
7.9 + 0.2 KV
good
Q5_K_S5.57
9.2 GB
8.9 + 0.2 KV
good
Q5_K_M5.7
9.4 GB
9.1 + 0.2 KV
good
Q6_K6.56
10.7 GB
10.5 + 0.2 KV
excellent
Q8_08.5
13.6 GB
13.4 + 0.2 KV
lossless
FP1616
25.0 GB
24.8 + 0.2 KV
lossless

Select your GPU above to see speed estimates and compatibility for each quantization.

Deploying for a team or in production? Size GPUs, cost & scaling in Enterprise →
▸ READY TO RUN THIS?RENT BY THE HOUR

RENT A GPU AND RUN MELLUM2.1 12B-A2.5B THINKING NOW

Rent on Vast.ai →Or RunPod →

Spin up an A100 / H100 / 4090 in ~60s. Pay by the second. Cancel anytime.

Community Ratings

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Benchmarks (3)

LiveCodeBench82.0
GPQA Diamond64.6
SWE-bench47.0

Run this model

▸Easiest way to get started·Beginners
DOCS ↗
curl -fsSL https://ollama.com/install.sh | sh
$ollama run other:12b-q4_K_M

Tag may need adjustment — check ollama.com/library/other for available tags.

▸ SETUP GUIDE
>_

Auto-setup with fitmyllm CLI

Detects your GPU, recommends the best model, downloads it, and starts chatting — zero config. Benchmarks your speed and contributes anonymous data to improve predictions.

pip install fitmyllmthen run fitmyllmLearn more
Auto-detect GPULive tok/s in chatSpeed benchmarks9 inference engines
HuggingFaceGGUF DownloadsBuild Hardware

GPUs that can run this model

At Q4_K_M quantization. Sorted by minimum VRAM.

NVIDIA RTX 4060 Ti 8GB
8 GB VRAM • 288 GB/s
NVIDIA
$399
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA RTX 4060
8 GB VRAM • 272 GB/s
NVIDIA
$299
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA RTX 3070 Ti
8 GB VRAM • 608 GB/s
NVIDIA
$499
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA RTX 3070
8 GB VRAM • 448 GB/s
NVIDIA
$325
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA RTX 3060 Ti
8 GB VRAM • 448 GB/s
NVIDIA
$250
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA RTX 3050 8GB
8 GB VRAM • 224 GB/s
NVIDIA
$249
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
AMD RX 7600
8 GB VRAM • 288 GB/s
AMD
$269
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
AMD RX 6650 XT
8 GB VRAM • 280 GB/s
AMD
$399
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
Intel Arc A750
8 GB VRAM • 512 GB/s
INTEL
$199
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
Apple M1 (8GB)
8 GB VRAM • 68 GB/s
APPLE
$499
Apple M2 (8GB)
8 GB VRAM • 100 GB/s
APPLE
$599
Apple M3 (8GB)
8 GB VRAM • 100 GB/s
APPLE
$599
NVIDIA RTX 2080 SUPER
8 GB VRAM • 496 GB/s
NVIDIA
$280
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA RTX 2080
8 GB VRAM • 448 GB/s
NVIDIA
$260
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA RTX 2070 SUPER
8 GB VRAM • 448 GB/s
NVIDIA
$240
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA RTX 2070
8 GB VRAM • 448 GB/s
NVIDIA
$200
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA RTX 2060 SUPER
8 GB VRAM • 448 GB/s
NVIDIA
$180
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA GTX 1080
8 GB VRAM • 320 GB/s
NVIDIA
$130
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA GTX 1070 Ti
8 GB VRAM • 256 GB/s
NVIDIA
$120
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA GTX 1070
8 GB VRAM • 256 GB/s
NVIDIA
$100
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA RTX 3060 8GB
8 GB VRAM • 224 GB/s
NVIDIA
$280
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
AMD RX 6600 XT
8 GB VRAM • 256 GB/s
AMD
$200
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
AMD RX 6600
8 GB VRAM • 224 GB/s
AMD
$165
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
AMD RX 5700 XT
8 GB VRAM • 448 GB/s
AMD
$150
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
AMD RX 5700
8 GB VRAM • 448 GB/s
AMD
$130
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
Intel Arc A580
8 GB VRAM • 512 GB/s
INTEL
$179
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA RTX 5060 Ti 8GB
8 GB VRAM • 448 GB/s
NVIDIA
$379
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA RTX 5060
8 GB VRAM • 448 GB/s
NVIDIA
$299
AmazonNeweggeBayPCPartPickerRent on RunPodRent on Vast.ai
NVIDIA Tesla K8
8 GB VRAM • 160 GB/s
NVIDIA
NVIDIA Tesla M60
8 GB VRAM • 160 GB/s
NVIDIA

Find the best GPU for Mellum2.1 12B-A2.5B Thinking

Build Hardware for Mellum2.1 12B-A2.5B Thinking
▸ SPEC SHEET

Mellum2.1 12B-A2.5B Thinking — 12.15B MoE.

▸ SPECIFICATIONS
PARAMETERS
12.15B (2.5B active)
ARCHITECTURE
Mixture of Experts
CONTEXT LENGTH
128K tokens
CAPABILITIES
chat, coding, reasoning, math, agentic, tool_use
RELEASE DATE
2026-10-08
PROVIDER
JetBrains
FAMILY
other
▸ VRAM REQUIREMENTS
QUANTBPWVRAMQUALITY
Q3_K_M46.6 GB88%
Q3_K_L4.37.0 GB90%
IQ4_XS4.467.3 GB92%
Q4_K_S4.677.6 GB93%
Q4_K_M4.897.9 GB94%
Q5_K_S5.578.9 GB96%
Q5_K_M5.79.1 GB96%
Q6_K6.5610.5 GB97%
Q8_08.513.4 GB100%
FP161624.8 GB100%
§ 01BENCHMARK SCORES
GPQA Diamond64.6
LiveCodeBench82.0
SWE-bench47.0
§ 03COMPATIBLE GPUs
30 @ Q4_K_M
NVIDIA RTX 4060 Ti 8GB
8 GB · 288 GB/s
NVIDIA RTX 4060
8 GB · 272 GB/s
NVIDIA RTX 3070 Ti
8 GB · 608 GB/s
NVIDIA RTX 3070
8 GB · 448 GB/s
NVIDIA RTX 3060 Ti
8 GB · 448 GB/s
NVIDIA RTX 3050 8GB
8 GB · 224 GB/s
AMD RX 7600
8 GB · 288 GB/s
AMD RX 6650 XT
8 GB · 280 GB/s
Intel Arc A750
8 GB · 512 GB/s
Apple M1 (8GB)
8 GB · 68 GB/s
Apple M2 (8GB)
8 GB · 100 GB/s
Apple M3 (8GB)
8 GB · 100 GB/s
NVIDIA RTX 2080 SUPER
8 GB · 496 GB/s
NVIDIA RTX 2080
8 GB · 448 GB/s
NVIDIA RTX 2070 SUPER
8 GB · 448 GB/s