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JetBrainsMellumLlamaForCausalLM

Mellum 4B Base — Hardware Requirements & GPU Compatibility

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Mellum 4B Base is a 4.0B-parameter open language model from JetBrains in the Mellum family. It supports a context window of up to 8,192 tokens. At Q4_K_M it needs about 3.47 GB of VRAM — see which GPUs and Macs can run it below.

4.0B params · dense8K contextApache 2.02.4K downloads449 likes286 quant downloads
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Runs great on a 24 GB GPU

Runs from8 GB Q4_K_M · 8KBest on24 GB Q4_K_M · ~189 tok/s · 8KMacs from8 GB Q4_K_M · ~21 tok/s

Apache 2.0

Reference GPU · RTX 4090 24 GB

Estimates, ±20% · how we estimate

Run Mellum 4B Base

One recommended way. Every other method, OS and quant is in the step-by-step guide.

Recommended

vLLM
one command · needs vLLM installed
$vllm serve JetBrains/Mellum-4b-base --max-model-len 8192

vLLM repo with its own quantisation

Download: Weights on Hugging Face

install, OS, other quants

Other ways

each opens step-by-step

Run in cloud

Fits on RTX 3060 12GB (6 GB headroom) · Q4_K_M

Generation speed
~67 tok/s
generation speed
Cost per 1M output tokens
$0.29
per 1M output tokens

How Much VRAM Does Mellum 4B Base Need?

Select a quantization level; the listed hardware adheres to it.

QuantizationVRAM+32KOn RTX 4090 (reference)
2.8 GB—2-bit · K-quant — 2-bit quantization with K-quant improvementsFits: 8K context · ~237 tok/s
3.0 GB—3-bit medium — 3-bit medium quantizationFits: 8K context · ~218 tok/s
3.5 GB—4-bit medium — 4-bit medium quantization — most popular sweet spotFits: 8K context · ~189 tok/s
3.9 GB—5-bit medium — 5-bit medium quantization — good quality/size tradeoffFits: 8K context · ~167 tok/s
4.4 GB—6-bit, very good — 6-bit quantization, very good qualityFits: 8K context · ~150 tok/s
5.1 GB—8-bit, near-lossless — 8-bit quantization, near-losslessFits: 8K context · ~129 tok/s
9.1 GB—16-bit · bfloat — Brain floating point 16 — preferred for trainingFits: 8K context · ~72 tok/s
est.calculated, no published file yet

Selected Q4_K_M

4-bit medium quantization

5.7GBat 8K context

Weights
2.4 GB
KV cache
3.0 GB
Overhead
0.3 GB

Fits RTX 4090 (reference) · 18.3 GB free · ~189 tok/s

≥50 tok/s needs ≥267 GB/s · RTX 5090 ~336, RTX 3090 Ti ~189

Which Hardware Can Run Mellum 4B Base?

Q4_K_M · 3.5 GB

Mellum 4B Base (Q4_K_M) requires 3.5 GB of VRAM to load the model weights. For comfortable inference with headroom for KV cache and system overhead, 5+ GB is recommended. Using the full 8K context window can add up to 2.3 GB, bringing total usage to 5.7 GB. 52 GPUs can run it, including NVIDIA GeForce RTX 5090, NVIDIA GeForce RTX 3090 Ti. 163 devices with unified memory can run Mellum 4B Base, including Mac Studio (M3 Ultra, 256GB), Mac Studio (M3 Ultra, 512GB), MacBook Air 13" M3 (8 GB).

By VRAM tier · typical GPUs and Macs at Q4_K_M
8 GB · RTX 4060Q4_K_M · 5.7 GB · ~51 tok/s · 8K8 GB tier →
12 GB · RTX 3060 12GBQ4_K_M · 5.7 GB · ~67 tok/s · 8K12 GB tier →
16 GB · RTX 5060 Ti 16GBQ4_K_M · 5.7 GB · ~84 tok/s · 8K16 GB tier →
24 GB · RTX 4090referenceQ4_K_M · 5.7 GB · ~189 tok/s · 8K24 GB tier →
Mac 32 GB · Mac Mini M4Q4_K_M · 5.7 GB · ~24 tok/s · 8KMacs →
Mac 64 GB · Mac Studio M4 MaxQ4_K_M · 5.7 GB · ~110 tok/s · 8KMacs →

Alternatives to Mellum 4B Base

Mellum family · 8 models →

Similar models

6
ModelScoreVRAMtok/sWhy it is similar
Granite Vision 4.1 4BIBM—4 GB~228same size
Medgemma 1.5 4B ITGoogle—5 GB~231same size
Qwen3 4B Instruct 2507Alibaba—4.2 GB~226same size
MiniCPM V 4OpenBMB—3.1 GB~236same size
Medgemma 4B ITGoogle—5 GB~231same size
Phi 4 Mini ReasoningMicrosoft—4.8 GB~228same size

Specifications

Publisher
JetBrains
Family
Mellum
Parameters
4.0B
Architecture
LlamaForCausalLM
Context Length
8,192 tokens
Vocabulary Size
98,304
Release Date
2025-04-28
License
Apache 2.0

Frequently Asked Questions

How much VRAM does Mellum 4B Base need?

Mellum 4B Base requires 3.5 GB of VRAM at Q4_K_M, or 9.1 GB at BF16. Full 8K context adds up to 2.3 GB (5.7 GB total).

VRAM = Weights + KV Cache + Overhead

Weights = 4.0B × 4.8 bits ÷ 8 = 2.4 GB

KV Cache + Overhead ≈ 1.1 GB (at 2K context + ~0.3 GB framework)

Fit ratings and hardware model lists check this model with room for a 16K-token context, which needs a little more memory.

KV Cache + Overhead ≈ 3.3 GB (at full 8K context)

VRAM usage by quantization

3.5 GB
5.7 GB

Learn more about VRAM estimation →

What's the best quantization for Mellum 4B Base?

For Mellum 4B Base, Q4_K_M (3.5 GB) offers the best balance of quality and VRAM usage. Q5_K_M (3.9 GB) provides better quality if you have the VRAM. The smallest option is Q2_K at 2.8 GB.

VRAM requirement by quantization

Q2_K
2.8 GB
Q4_K_M ★
3.5 GB
Q5_K_M
3.9 GB
Q6_K
4.4 GB
Q8_0
5.1 GB
BF16
9.1 GB

★ Recommended — best balance of quality and VRAM usage.

Learn more about quantization →

Can I run Mellum 4B Base on a Mac?

Yes — MacBook Air 13" M3 (8 GB) and 145 other Macs can run Mellum 4B Base. Apple Silicon uses unified memory, so the model shares RAM with the system. At Q4_K_M you need at least 3.5 GB of usable unified memory (RAM minus macOS overhead).

Can I run Mellum 4B Base locally?

Yes — Mellum 4B Base can run locally on consumer hardware. Popular tools include Ollama, LM Studio, and llama.cpp.

How fast is Mellum 4B Base?

At Q4_K_M, Mellum 4B Base can reach ~1383 tok/s on AMD Instinct MI350X. On NVIDIA GeForce RTX 4090: ~189 tok/s. Speed depends mainly on GPU memory bandwidth. Real-world results typically within ±20%.

tok/s = (bandwidth GB/s ÷ model GB) × efficiency

Example: NVIDIA B200 → 8000 ÷ 3.47 × 0.65 = ~1499 tok/s

Estimated speed at Q4_K_M (3.5 GB)

~1499 tok/s
~189 tok/s
~1499 tok/s
~1383 tok/s

Real-world results typically within ±20%. Speed depends on batch size, quantization kernel, and software stack.

Learn more about tok/s estimation →

What's the download size of Mellum 4B Base?

At Q4_K_M, the download is about 2.41 GB. The full-precision BF16 version is 8.04 GB. The smallest option (Q2_K) is 1.71 GB.

Which GPUs can run Mellum 4B Base?

52 consumer GPUs can run Mellum 4B Base at Q4_K_M. Top options include AMD Radeon RX 6700 XT, AMD Radeon RX 6800, AMD Radeon RX 6800 XT. 52 GPUs have plenty of headroom for comfortable inference.

Which devices can run Mellum 4B Base?

163 devices with unified memory can run Mellum 4B Base at Q4_K_M (3.5 GB), including AMD Ryzen AI 9 HX 370 (Strix Point) Laptop, ASUS Ascent GX10, Beelink GTR9 Pro (Ryzen AI Max+ 395, 128 GB), Framework Desktop (Ryzen AI Max+ 395, 128 GB). Apple Silicon Macs use unified memory shared between CPU and GPU, making them well-suited for local LLM inference.