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Qwen3.5 397B-A17B VRAM Requirements

Alibaba, China · Released February 16, 2026

Qwen3.5 397B-A17B has 403.4B parameters (17B active per token). In BF16 its weights alone take 739 GiB; quantized to 4-bit, about 223 GiB. Each 32K-token request adds 0.94 GiB of KV cache. Cheapest way to run it today: 7 × NVIDIA A100 40GB at $2.62 per hour.

Size your own setup in the calculator →

VRAM by precision and context length

Weights plus the KV cache of one request (BF16 cache) and the model's fixed recurrent state, in GiB. Add 1 to 3 GiB for the inference engine itself.

Weights formatWeights only+ 8K context+ 32K context+ 128K context+ 256K context
BF16 / FP16739740740743747
FP8 / INT8371372373375379
4-bit (GGUF Q4_K_M)223223224227231

Qwen3.5 397B-A17B GGUF files

Exact size of each quantization in unsloth/Qwen3.5-397B-A17B-GGUF (opens in a new tab), and the smallest GPU that runs it with llama.cpp, Ollama or LM Studio and an 8K-token context.

QuantizationFile sizeSmallest GPU
BF16739 GiBMore than 96 GB: see the calculator
UD-Q8_K_XL398 GiBMore than 96 GB: see the calculator
Q8_0393 GiBMore than 96 GB: see the calculator
UD-Q6_K_XL337 GiBMore than 96 GB: see the calculator
Q6_K304 GiBMore than 96 GB: see the calculator
UD-Q6_K304 GiBMore than 96 GB: see the calculator
UD-Q5_K_XL275 GiBMore than 96 GB: see the calculator
Q5_K_M273 GiBMore than 96 GB: see the calculator
UD-Q5_K_M273 GiBMore than 96 GB: see the calculator
Q5_K_S258 GiBMore than 96 GB: see the calculator
UD-Q5_K_S258 GiBMore than 96 GB: see the calculator
UD-Q4_K_XL228 GiBMore than 96 GB: see the calculator
Q4_K_M227 GiBMore than 96 GB: see the calculator
UD-Q4_K_M227 GiBMore than 96 GB: see the calculator
MXFP4_MOE221 GiBMore than 96 GB: see the calculator
Q4_K_S212 GiBMore than 96 GB: see the calculator
UD-Q4_K_S212 GiBMore than 96 GB: see the calculator
UD-IQ4_NL180 GiBMore than 96 GB: see the calculator
UD-IQ4_XS177 GiBMore than 96 GB: see the calculator
UD-Q3_K_XL166 GiBMore than 96 GB: see the calculator
Q3_K_M165 GiBMore than 96 GB: see the calculator
UD-Q3_K_M165 GiBMore than 96 GB: see the calculator
Q3_K_S153 GiBMore than 96 GB: see the calculator
UD-Q3_K_S153 GiBMore than 96 GB: see the calculator
UD-IQ3_S136 GiBMore than 96 GB: see the calculator
UD-IQ3_XXS131 GiBMore than 96 GB: see the calculator
UD-IQ2_M115 GiBMore than 96 GB: see the calculator
UD-IQ2_XXS107 GiBMore than 96 GB: see the calculator
UD-IQ1_M99.5 GiBMore than 96 GB: see the calculator

Read every day from Hugging Face. Split files are added together; vision projectors are left out.

How many GPUs to run Qwen3.5 397B-A17B

Fewest GPUs that fit the weights plus one 8K-token request. Data-center GPUs use vLLM (90% of memory usable), the others llama.cpp. Several GPUs split the model with tensor or pipeline parallelism.

GPUBF16 / FP168-bit4-bit
GeForce RTX 4090 24 GB48 (several servers)24 (several servers)16 (several servers)
GeForce RTX 5090 32 GB32 (several servers)16 (several servers)8
RTX PRO 6000 Blackwell 96 GB16 (several servers)53
Mac M5 Max 128 GB 96 GB usable16 (several servers)53
NVIDIA H100 80 GB16 (several servers)64
NVIDIA H200 141 GB742
NVIDIA B200 (HGX) 180 GB532

8-bit: FP8 with vLLM (INT8 on GPUs without FP8), Q8_0 with llama.cpp. 4-bit: AWQ / GPTQ with vLLM, Q4_K_M with llama.cpp, both counted at the Q4_K_M size.

Cheapest way to run Qwen3.5 397B-A17B today

For each GPU: the fewest cards that fit Qwen3.5 397B-A17B with one 8K-token request, the most faithful weight format at that count, and the cheapest on-demand price (2026-10-12).

On-demand prices from RunPod, Vast.ai, Verda and Azure, checked every hour. Serving many users needs more KV cache, so more memory: size it in the calculator. Some links are affiliate links: StudioTV may earn a commission, at no extra cost to you.

KV cache: how memory grows with context

Architecture: 60 layers · 15 full attention (2 KV × 256) · 45 linear attention. Its KV cache is 4.0× smaller than if every layer used full attention, because only 15 of its 60 layers keep a KV cache; the others hold a small fixed-size state. Only 17B parameters are active per token, but all 403B must sit in memory: VRAM depends on the total, speed on the active part.

Context per requestBF16 cacheFP8 cache
8K tokens0.23 GiB0.12 GiB
32K tokens0.94 GiB0.47 GiB
128K tokens3.75 GiB1.88 GiB
256K tokens7.50 GiB3.75 GiB

Plus 183 MiB of recurrent state per request, whatever the context.

Qwen3.5 397B-A17B VRAM FAQ

How much VRAM does Qwen3.5 397B-A17B need?

In BF16 the weights alone take 739 GiB (794 GB). In FP8 that is 371 GiB, and about 223 GiB with 4-bit quantization (Q4_K_M). Each request then adds KV cache: 0.23 GiB at 8K tokens and 0.94 GiB at 32K (BF16 cache).

Can Qwen3.5 397B-A17B run on a single RTX 4090 (24 GB)?

No. Even in 4-bit it needs 16 (several servers) RTX 4090s. In 4-bit it needs 4 H100 GPUs.

What is the cheapest way to run Qwen3.5 397B-A17B?

On 2026-10-12, the cheapest on-demand setup is 7 × NVIDIA A100 40GB with 4-bit weights on Vast.ai, at $2.62 per hour (about $1,911.14 per month). Next: 6 × RTX 6000 Ada (48 GB) with Q4_K_M weights on Vast.ai, at $3.23 per hour. Sized for one 8K-token request; prices are checked every hour.

How many H100 GPUs does Qwen3.5 397B-A17B need?

With one request and an 8K-token context: 16 (several servers) in BF16, 6 in FP8 and 4 in 4-bit (vLLM, 90% of memory usable). Serving many users at once needs more memory for their KV caches: the calculator sizes that for you.

Qwen3.5 397B-A17B VRAM badge

For a model card or a README: the 4-bit size and the smallest GPU it fits on, linked to this page. Data as JSON: /api/models/qwen3-5-397b-a17b.json.

Qwen3.5 397B-A17B VRAM badge

[![Qwen3.5 397B-A17B VRAM](https://studiotvai.com/badge/qwen3-5-397b-a17b.svg)](https://studiotvai.com/vram-requirements/qwen3-5-397b-a17b)

Other models

Same family (large moe): MiniMax M2.7 · DeepSeek R1 · Kimi K2.6 · GLM-5.3 · GLM-5.3-Flash · DeepSeek V4 Flash · DeepSeek V4 Pro · DeepSeek V4.1 Flash · MiMo-V2.6 Pro · MiMo-V2.6 Flash · Kimi K3 · Mistral Large 4 · DeepSeek V4 Flash Vision Exp · Qwen3.8 2.4T-A95B · Ornith 1.5 397B · Atria Dawn Preview · Intern S2 397B · DeepSeek-V3 · DeepSeek-V3.1 · Kimi-K2.7-Code · Kimi-K2.5 · Kimi-K2 · GLM-5.2 · GLM-5.1 · GLM-5 · MiniMax-M2.5 · MiniMax-M2 · MiMo-V2.5 · Ornith-1.0 397B · Qwen3 235B-A22B

All models: Llama 3.1 8B · Mistral Small 3.2 24B · Qwen3 32B · Llama 3.3 70B · Llama 3.1 405B · Qwen3.5 4B · Qwen3.5 9B · Qwen3.8 27B · Qwen3.6 35B-A3B · Qwen3.5 122B-A10B · Qwen3.8-Flash-Next · LFM2.5 8B-A1B · LFM2 24B-A2B · Gemma 4 12B · Gemma 4 31B · Gemma 4 26B-A4B · gpt-oss 20B · gpt-oss 120B · Llama 4 Scout 17B-16E · Llama 4 Maverick 17B-128E · Kolibri-1 · Nemotron 3 Nano 30B-A3B · Nemotron 3 Super 120B-A12B · MiniMax M2.7 · DeepSeek R1 · Kimi K2.6 · GLM-5.3 · GLM-5.3-Flash · DeepSeek V4 Flash · DeepSeek V4 Pro · DeepSeek V4.1 Flash · MiMo-V2.6 Pro · MiMo-V2.6 Flash · Kimi K3 · Mistral Large 4 · Qwen3-Coder-Next 80B-A3B · Qwen3-Coder 30B-A3B · Qwen3-Coder 480B-A35B · DeepSeek V4 Flash Vision Exp · Qwen3.8 2.4T-A95B · Ornith 1.5 397B · Ornith 1.5 35B-A3B · Ornith 1.5 9B · Atria Dawn Preview · Intern S2 397B · Clef · Clef Flash · D1 3B · Humanizer · JEV 27B VL · Mellum2.1 12B-A2.5B · LightOnOCR-3 4B · Spark-X2.5 4B · Agnes-3.0-Qwen · Youtu-Parsing-Omni · Agnes-3.0-Flash · Mistral 7B-v0.3 · Mistral-Small-3.1 24B · Mistral-Nemo · Ministral 8B · DeepSeek-V3 · DeepSeek-R1-Qwen3 8B · DeepSeek-R1-Distill-Qwen 32B · DeepSeek-V3.1 · DeepSeek-R1-Distill-Qwen 14B · DeepSeek-R1-Distill-Qwen 7B · DeepSeek-R1-Distill-Llama 8B · Qwen3 4B · Qwen3 8B · Qwen2.5 7B · Qwen3 14B · Qwen2.5 3B · Qwen3.6 27B · Qwen3.5 27B · Qwen2.5-Coder 7B · Qwen2.5 32B · Qwen2.5-Coder 14B · Qwen3.5 35B-A3B · Qwen3 30B-A3B · Qwen2.5 14B · Qwen2.5-Coder 32B · Kimi-K2.7-Code · Kimi-K2.5 · Kimi-K2 · GLM-5.2 · GLM-5.1 · GLM-5 · MiniMax-M2.5 · MiniMax-M2 · MiMo-V2.5 · Ornith-1.0 397B · Qwen2.5-Coder 3B · Qwen3 235B-A22B · gemma-4-E4B · gemma-4-E2B · NVIDIA-Nemotron-3-Nano 4B · NVIDIA-Nemotron-3.5-Lightning 30B-A3B

Estimates, not guarantees: computed from the official config.json with the same engine as the LLM VRAM Calculator. Real usage depends on your engine version and settings.