Hermes 4 405B — Hardware Requirements & GPU Compatibility
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Hermes 4 405B is a 405.9B-parameter open language model from Nous Research in the Hermes family. It supports a context window of up to 131,072 tokens. At Q4_K_M it needs about 244.87 GB of VRAM — see which GPUs and Macs can run it below.
546 downloads
85 likesSpecifications
- Publisher
- Nous Research
- Family
- Hermes
- Parameters
- 405.9B
- Architecture
- LlamaForCausalLM
- Context Length
- 131,072 tokens
- Vocabulary Size
- 128,256
- Release Date
- 2025-08-06
- License
- Llama 3 Community
Get Started
HuggingFace
How Much VRAM Does Hermes 4 405B Need?
Select a quantization to see compatible GPUs below.
| Quantization | Bits | VRAM | + Context | File Size | Quality |
|---|---|---|---|---|---|
| Q2_Kest. | 3.40 | 173.8 GB | 240.4 GB | 172.49 GB | 2-bit quantization with K-quant improvements |
| Q3_K_Mest. | 3.90 | 199.2 GB | 265.8 GB | 197.85 GB | 3-bit medium quantization |
| Q4_K_Mest. | 4.80 | 244.9 GB | 311.5 GB | 243.51 GB | 4-bit medium quantization — most popular sweet spot |
| Q5_K_Mest. | 5.70 | 290.5 GB | 357.1 GB | 289.17 GB | 5-bit medium quantization — good quality/size tradeoff |
| Q6_Kest. | 6.60 | 336.2 GB | 402.8 GB | 334.83 GB | 6-bit quantization, very good quality |
| Q8_0est. | 8.00 | 407.2 GB | 473.8 GB | 405.85 GB | 8-bit quantization, near-lossless |
| BF16est. | 16.00 | 813.1 GB | 879.6 GB | 811.71 GB | Brain floating point 16 — preferred for training |
est.= calculated VRAM estimate; no published GGUF file found for that quantization yet. Other rows are verified against real community uploads.
Which GPUs Can Run Hermes 4 405B?
Q4_K_M · 244.9 GBHermes 4 405B (Q4_K_M) requires 244.9 GB of VRAM to load the model weights. For comfortable inference with headroom for KV cache and system overhead, 319+ GB is recommended. Using the full 131K context window can add up to 66.6 GB, bringing total usage to 311.5 GB. No single GPU has enough memory — multi-GPU or cluster setups are needed.
Which Devices Can Run Hermes 4 405B?
Q4_K_M · 244.9 GB3 devices with unified memory can run Hermes 4 405B, including NVIDIA DGX H100, NVIDIA DGX A100 640GB.
Runs great
— Plenty of headroomRelated Models
Frequently Asked Questions
- How much VRAM does Hermes 4 405B need?
Hermes 4 405B requires 244.9 GB of VRAM at Q4_K_M, or 813.1 GB at BF16. Full 131K context adds up to 66.6 GB (311.5 GB total).
VRAM = Weights + KV Cache + Overhead
Weights = 405.9B × 4.8 bits ÷ 8 = 243.5 GB
KV Cache + Overhead ≈ 1.4 GB (at 2K context + ~0.3 GB framework)
KV Cache + Overhead ≈ 68 GB (at full 131K context)
VRAM usage by quantization
Q4_K_M244.9 GBQ4_K_M + full context311.5 GB- Can NVIDIA GeForce RTX 5090 run Hermes 4 405B?
No — Hermes 4 405B requires at least 173.8 GB at Q2_K, which exceeds the NVIDIA GeForce RTX 5090's 32 GB of VRAM.
- What's the best quantization for Hermes 4 405B?
For Hermes 4 405B, Q4_K_M (244.9 GB) offers the best balance of quality and VRAM usage. Q5_K_M (290.5 GB) provides better quality if you have the VRAM. The smallest option is Q2_K at 173.8 GB.
VRAM requirement by quantization
Q2_K173.8 GBQ4_K_M ★244.9 GBQ5_K_M290.5 GBQ6_K336.2 GBQ8_0407.2 GBBF16813.1 GB★ Recommended — best balance of quality and VRAM usage.
- Can I run Hermes 4 405B on a Mac?
Hermes 4 405B requires at least 173.8 GB at Q2_K, which exceeds the unified memory of most consumer Macs. You would need a Mac Studio or Mac Pro with a high-memory configuration.
- Can I run Hermes 4 405B locally?
Yes — Hermes 4 405B can run locally on consumer hardware. At Q4_K_M quantization it needs 244.9 GB of VRAM. Popular tools include Ollama, LM Studio, and llama.cpp.
- How fast is Hermes 4 405B?
At Q4_K_M, Hermes 4 405B can reach ~18 tok/s on AMD Instinct MI350X. Speed depends mainly on GPU memory bandwidth. Real-world results typically within ±20%.
tok/s = (bandwidth GB/s ÷ model GB) × efficiency
Example: NVIDIA B300 → 8000 ÷ 244.9 × 0.65 = ~21 tok/s
Estimated speed at Q4_K_M (244.9 GB)
~21 tok/s~18 tok/s~18 tok/sReal-world results typically within ±20%. Speed depends on batch size, quantization kernel, and software stack.
- What's the download size of Hermes 4 405B?
At Q4_K_M, the download is about 243.51 GB. The full-precision BF16 version is 811.71 GB. The smallest option (Q2_K) is 172.49 GB.
- Which GPUs can run Hermes 4 405B?
No single consumer GPU has enough VRAM to run Hermes 4 405B at Q4_K_M (244.9 GB). Multi-GPU or professional hardware is required.
- Which devices can run Hermes 4 405B?
4 devices with unified memory can run Hermes 4 405B at Q4_K_M (244.9 GB), including Mac Studio (M3 Ultra, 256GB), Mac Studio (M3 Ultra, 512GB), NVIDIA DGX A100 640GB, NVIDIA DGX H100. Apple Silicon Macs use unified memory shared between CPU and GPU, making them well-suited for local LLM inference.