llmrun
NVIDIANemotronNemotronHForCausalLM

NVIDIA Nemotron 3 Ultra 550B A55B BF16 — Hardware Requirements & GPU Compatibility

ChatFunctions

NVIDIA-Nemotron-3-Ultra-550B-A55B-BF16 is NVIDIA's large hybrid reasoning model, combining Mamba-2, Mixture-of-Experts, and attention layers with multi-token prediction in a single architecture. It has around 560 billion total parameters with about 55 billion active per token, reasoning can be toggled on or off through its chat template, and NVIDIA positions it for frontier reasoning, complex agentic workflows, long-context analysis, and high-stakes retrieval-augmented generation across ten languages. It supports a 262,144-token context window and is released under a custom OpenMDW license. NVIDIA's own stated minimum is 8 GB200/B200-class GPUs or equivalent, so this is squarely server hardware; most people will need a hosted or cloud deployment rather than a local one.

560.5B params · MoE57B active262K contextOther956.9K downloads367 likes7.8K quant downloads

NVIDIA Nemotron 3 Ultra 550B A55B BF16 runs on a 512 GB+ Mac or a multi-GPU server

Best local pick → Mac Studio (M3 Ultra, 512GB) · Q4_K_M · 378.4 GB · ~13 tok/s

Macs from192 GB IQ2_XXS · ~25 tok/s

Score 109.9#26 of 100 open#23 of 96 that fit ≤512 GBOther

Not set up for it?

Reference GPU · RTX 4090 24 GB

Estimates, ±20% · how we estimate

Run NVIDIA Nemotron 3 Ultra 550B A55B BF16

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

Recommended

vLLM on a multi-GPU server
tensor + pipeline parallel · needs vLLM on every node
$vllm serve nvidia/NVIDIA-Nemotron-3-Ultra-550B-A55B-BF16 --max-model-len 16384 --tensor-parallel-size 8

Size the nodes from the table above

Download: UD-Q4_K_M/NVIDIA-Nemotron-3-Ultra-550B-A55B-UD-Q4_K_M-00001-of-00009.gguf359.23 GB + 8 partsunsloth

install, other ways

Other ways

each opens step-by-step

Run in cloud

Rent 6× H100 SXM · Q4_K_M

Estimated hourly price
~$13.27/hr
est., whole server
GPUs
6 GPUs
480 GB of VRAM

How Much VRAM Does NVIDIA Nemotron 3 Ultra 550B A55B BF16 Need?

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

QuantizationVRAM+32KRuns on
169.6 GB187.6 GB2-bit · i-quant extreme compression — Importance-weighted 2-bit, extreme compression — significant quality lossRuns on B200 192 GB
185.0 GB203 GB2-bit · i-quant extra small — Importance-weighted 2-bit, extra smallRuns on Instinct MI325X 256 GB
262.1 GB280.1 GB2-bit · K-quant — 2-bit quantization with K-quant improvementsRuns on Instinct MI350X 288 GB
300.6 GB318.7 GB3-bit medium — 3-bit medium quantizationRuns on 5× H100 SXM 80 GB
369.9 GB388 GB4-bit medium — 4-bit medium quantization — most popular sweet spotRuns on 6× H100 SXM 80 GB
439.3 GB457.4 GB5-bit medium — 5-bit medium quantization — good quality/size tradeoffRuns on 7× H100 SXM 80 GB
508.7 GB526.8 GB6-bit, very good — 6-bit quantization, very good qualityRuns on 8× H100 SXM 80 GB
616.6 GB634.7 GB8-bit, near-lossless — 8-bit quantization, near-losslessRuns on 5× H200 SXM 141 GB

Selected Q4_K_M

4-bit medium quantization

378.4GBat 16K context

Weights
368.5 GB
KV cache
9.6 GB
Overhead
0.3 GB

Server-class: ~378.4 GB at 16K context · about 6× H100 SXM 80 GB

Which Hardware Can Run NVIDIA Nemotron 3 Ultra 550B A55B BF16?

Q4_K_M · 369.9 GB

NVIDIA Nemotron 3 Ultra 550B A55B BF16 (Q4_K_M) requires 369.9 GB of VRAM to load the model weights. For comfortable inference with headroom for KV cache and system overhead, 481+ GB is recommended. No consumer GPU has enough memory. 1 device with unified memory can run NVIDIA Nemotron 3 Ultra 550B A55B BF16, including Mac Studio (M3 Ultra, 512GB).

By VRAM tier · typical GPUs and Macs at Q4_K_M

Consumer GPUs (up to 32 GB) and Macs up to 128 GB: too small for this model (needs ≥ 178 GB)8 GB tier →12 GB tier →16 GB tier →24 GB tier →Macs →

How good is NVIDIA Nemotron 3 Ultra 550B A55B BF16?

The llmrun Score merges 17 public benchmark boards into a single figure, where 100 represents the average for open models.

Score vs VRAM in the ≤512 GB tier

  • NVIDIA Nemotron 3 Ultra 550B A55B BF16
  • Other models
  • Best Score for its VRAM

#23 of 96 that fit ≤512 GB

Each dot is a model at the best quant that fits ≤512 GB. The line joins the models with the best Score for their VRAM; a dot below it is beaten by a model that needs no more memory.

Full ≤512 GB ranking →

Benchmarks

The 6 boards that weigh most in the llmrun Score, of 22 with a result for this model; badges show who ran the test.

In the ≤512 GB class

96 models fit ≤512 GB

Same Score, only models that fit ≤512 GB at their best quant: this model's peers by memory need.

  1. #1

    133.4

    499.3 GB

  2. #2

    131.9

    186.5 GB

  3. #3

    130.1

    453.8 GB

  4. #4

    129.5

    458.4 GB

  5. #5

    127.6

    183.0 GB

  6. #6

    125.3

    461.5 GB

Alternatives to NVIDIA Nemotron 3 Ultra 550B A55B BF16

Nemotron family · 42 models →

Official models with an llmrun Score, each answering one question; sizes are each model's default quant (usually Q4_K_M) with a 16K-token context.

Similar models

10
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MiniMax M3MiniMax112.5258 GBsimilar score
GLM 5Z.ai111.6454.1 GBsimilar score
Qwen3.6 27BAlibaba111.217.9 GBsimilar score
DeepSeek V3.2DeepSeek110.4412.7 GBsimilar score
DeepSeek V4 FlashDeepSeek109.3175.1 GBsimilar score
GLM 4.7Z.ai109.1217.9 GBsimilar score
Qwen3 235B A22B Thinking 2507Alibaba108.2142.9 GBsimilar score
Fine-tunes & variants(2)

Specifications

Publisher
NVIDIA
Family
Nemotron
Parameters
560.5B
Active parameters
57B per token
Architecture
NemotronHForCausalLM
Context Length
262,144 tokens
Vocabulary Size
131,072
Release Date
2026-06-03
License
Other

Frequently Asked Questions

How much VRAM does NVIDIA Nemotron 3 Ultra 550B A55B BF16 need?

NVIDIA Nemotron 3 Ultra 550B A55B BF16 requires 369.9 GB of VRAM at Q4_K_M, or 1233.2 GB at BF16.

VRAM = Weights + KV Cache + Overhead

Weights = 560.5B × 4.8 bits ÷ 8 = 336.3 GB

KV Cache + Overhead ≈ 33.6 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.

VRAM usage by quantization

369.9 GB

Learn more about VRAM estimation →

Can NVIDIA GeForce RTX 5090 run NVIDIA Nemotron 3 Ultra 550B A55B BF16?

No — NVIDIA Nemotron 3 Ultra 550B A55B BF16 requires at least 169.6 GB at IQ2_XXS, which exceeds the NVIDIA GeForce RTX 5090's 32 GB of VRAM.

What's the best quantization for NVIDIA Nemotron 3 Ultra 550B A55B BF16?

For NVIDIA Nemotron 3 Ultra 550B A55B BF16, Q4_K_M (369.9 GB) offers the best balance of quality and VRAM usage. Q5_K_S (423.9 GB) provides better quality if you have the VRAM. The smallest option is IQ2_XXS at 169.6 GB.

VRAM requirement by quantization

IQ2_XXS
169.6 GB
Q2_K
262.1 GB
IQ4_NL
346.8 GB
Q4_K_M ★
369.9 GB
Q5_K_S
423.9 GB
BF16
1233.2 GB

★ Recommended — best balance of quality and VRAM usage.

Learn more about quantization →

Can I run NVIDIA Nemotron 3 Ultra 550B A55B BF16 on a Mac?

Yes — Mac Pro M2 Ultra (192 GB) and 3 other Macs can run NVIDIA Nemotron 3 Ultra 550B A55B BF16, the smallest at IQ2_XXS. Apple Silicon uses unified memory, so the model shares RAM with the system. At Q4_K_M you need at least 369.9 GB of usable unified memory (RAM minus macOS overhead), from Mac Studio (M3 Ultra, 512GB).

Can I run NVIDIA Nemotron 3 Ultra 550B A55B BF16 locally?

Yes — NVIDIA Nemotron 3 Ultra 550B A55B BF16 can run locally on consumer hardware. Popular tools include Ollama, LM Studio, and llama.cpp.

What's the download size of NVIDIA Nemotron 3 Ultra 550B A55B BF16?

At Q4_K_M, the download is about 336.31 GB. The full-precision BF16 version is 1121.05 GB. The smallest option (IQ2_XXS) is 154.14 GB.

Which GPUs can run NVIDIA Nemotron 3 Ultra 550B A55B BF16?

No single consumer GPU has enough VRAM to run NVIDIA Nemotron 3 Ultra 550B A55B BF16 at Q4_K_M (369.9 GB). Multi-GPU or professional hardware is required.

Which devices can run NVIDIA Nemotron 3 Ultra 550B A55B BF16?

1 device with unified memory can run NVIDIA Nemotron 3 Ultra 550B A55B BF16 at Q4_K_M (369.9 GB), including Mac Studio (M3 Ultra, 512GB). Apple Silicon Macs use unified memory shared between CPU and GPU, making them well-suited for local LLM inference.