Qwen3 Coder 480B-A35B on H100 80GB SXM (80GB) — VRAM, KV Cache & Throughput

Qwen3 Coder 480B-A35B (480B total, 35B active, Sparse MoE + GQA) uses 271.39 GiB of 4-bit weights (Q4_K_M), requiring 273.9 GiB total at 8K context and 279.71 GiB at 32K on H100 80GB SXM (~3.4 tok/s decode).

Interactive Sizing Workbench

Full Compatibility Report →
80 GB · 3350 GB/s
Exceeds Available GPU Memory
Config-derived formula HF config.json ↗
Memory Allocation Breakdown (GiB) 273.9 GiB (294.1 GB) / 80 GiB (342%)
Model Weights: 271.39 GiB KV Cache & State: 1.94 GiB Runtime & Activation Buffers: 0.57 GiB System RAM Offload: 0 GiB
Required GPU Memory
273.9 GiB
294.1 GB (decimal)
Usable Hardware Memory
76 GiB
80 GB (physical)
Safe Headroom
-197.9 GiB
342% utilization
Est. Decode Throughput
~3.4 tok/s
35B active params
Est. Prefill Throughput
~7347 tok/s
4K Prompt TTFT: ~558 ms
Est. Cost / 1M Tokens
$977.12
Sparse MoE + GQA · Apache-2.0

Recommended Hardware for Current Configuration

Best Single GPU
Multi-GPU Required
—
Best Value / Used GPU
2x B200 180GB
360GB · ~$80,000
Apple Unified Memory
Mac Studio M3 Ultra 512GB
~$9,500
Cloud From
RunPod · $11.96 / hr
2x B200 180GB

Production Launch Commands

llama.cpp (GGUF)
llama-server -hf unsloth/Qwen3-Coder-480B-A35B-Instruct-GGUF:Q4_K_M \
  --ctx-size 8192 -ngl 999 --flash-attn
vLLM
vllm serve Qwen/Qwen3-Coder-480B-A35B-Instruct \
  --max-model-len 8192 --gpu-memory-utilization 0.92
Live Token Speed Simulator (TTFT ~558ms · ~3.4 tok/s)
[Qwen3 Coder 480B-A35B · 273.9 GiB] allocated on target GPU. Prefill completed in TTFT window; streaming autoregressive tokens at memory-bandwidth-bound rate...

Cloud GPU Comparison & Rent-vs-Buy TCO

Verified public rates across RunPod, Vast.ai, Vultr, and DigitalOcean.

Verified: 2026-11-04
Purchase break-even
~17.4 months
Est. local power: $14.9 / mo
Provider Recommended Instance Total VRAM Hourly Rate Monthly at Selected Hours Billing Mode Deploy
RunPod 2x B200 180GB (Community Cloud) 360 GB $11.96 / hr $1454.34 / mo Per-second Deploy GPU ↗
Vast.ai 2x B200 180GB (Verified Host) 360 GB $15.00 / hr $1824.49 / mo Spot / On-demand Deploy GPU ↗
Vultr ($300 Free Credit*) 8x A100 80GB SXM (Dedicated Instance · $300 Credit*) 640 GB $19.18 / hr $2331.80 / mo Hourly Deploy GPU ↗
Vultr Cloud GPU 8x A100 80GB SXM (Dedicated Instance) 640 GB $19.18 / hr $2331.80 / mo Hourly Deploy GPU ↗
DigitalOcean 8x Instinct MI300X 192GB (Dedicated Instance) 1536 GB $20.72 / hr $2519.55 / mo Per-second Deploy GPU ↗

Rates reflect public listings on the verification date and fluctuate with regional inventory.

Fine-Tuning VRAM Requirements (QLoRA / LoRA / Full) — Qwen3 Coder 480B-A35B

QLoRA (4b) Exceeds Available GPU Memory
277.43 GiB
Model Weights: 271.39 GiB · Gradients + Optimizer: 4.9 GiB · Act: 1.14 GiB
Recommended GPU: 2x B200 180GB (360GB)
LoRA (16b) Exceeds Available GPU Memory
903.29 GiB
Model Weights: 894.07 GiB · Gradients + Optimizer: 7.7 GiB · Act: 1.52 GiB
Recommended GPU: 8x H200 141GB SXM (1128GB)
Full BF16 Exceeds Available GPU Memory
3668.38 GiB
Model Weights: 894.07 GiB · Gradients + Optimizer: 2771.62 GiB · Act: 2.69 GiB
Recommended GPU: Multi-GPU Required

Engineering Sizing Notes & Optimization Playbook

Quick Hardware Verdict

A single H100 80GB SXM (80GB) cannot hold 4-bit Qwen3 Coder 480B-A35B (273.9 GiB at 8K) entirely in VRAM. Use multi-GPU tensor parallelism, offload layers to system RAM, or deploy on a larger cloud GPU.

KV Cache & Runtime Tuning

Qwen3 Coder 480B-A35B uses Sparse MoE + GQA (480B total, 35B active per token). Moving from 8K to 32K context expands FP16 KV cache from 1.94 GiB to 7.75 GiB; enabling 8-bit KV cache (llama.cpp -ctk q8_0 -ctv q8_0 or vLLM --kv-cache-dtype fp8) saves 3.87 GiB at 32K (reducing total VRAM to 275.84 GiB).

VRAM Scaling Across Context Windows (4K to 128K, 4-bit Weights)

Qwen3 Coder 480B-A35B VRAM scaling from 4K to 128K context (4K: 272.92 GiB, 8K: 273.9 GiB, 32K: 279.71 GiB, 128K: 302.96 GiB) 4K 272.92 GiB (KV 0.97 GiB) 8K 273.9 GiB (KV 1.94 GiB) 32K 279.71 GiB (KV 7.75 GiB) 128K 302.96 GiB (KV 31 GiB) H100 80GB SXM (80GB)
Model weights remain constant while attention KV cache grows with context length and batch size.

Quantization Precision & Memory Matrix — Qwen3 Coder 480B-A35B @ 8K

Quantization Format Weights (GiB) KV Cache Total VRAM (GiB) Decode Speed Compatibility (H100 80GB SXM) Recommended GPU Data Source
Native Weights (BF16 / FP8 / MXFP4 — Lossless) (BF16) 894.07 GiB 1.94 GiB 896.58 GiB (962.7 GB) ~0.9 tok/s Exceeds Available GPU Memory Multi-GPU Required Official checkpoint size
FP8 / GGUF Q8_0 (8-bit — Near-Lossless) (Q8_0) 474.97 GiB 1.94 GiB 477.48 GiB (512.69 GB) ~1.7 tok/s Exceeds Available GPU Memory Multi-GPU Required Config-derived formula
GGUF Q6_K (6-bit — High Precision) (Q6_K) 366.57 GiB 1.94 GiB 369.08 GiB (396.3 GB) ~2.4 tok/s Exceeds Available GPU Memory Multi-GPU Required Config-derived formula
GGUF Q5_K_M (5-bit — Balanced) (Q5_K_M) 318.14 GiB 1.94 GiB 320.65 GiB (344.3 GB) ~2.8 tok/s Exceeds Available GPU Memory Multi-GPU Required Config-derived formula
Q4_K_M / UD-Q4_K_XL / AWQ (4-bit — Recommended) (Q4_K_M) 271.39 GiB 1.94 GiB 273.9 GiB (294.1 GB) ~3.4 tok/s Exceeds Available GPU Memory Multi-GPU Required Config-derived formula
GGUF IQ4_XS (4.25-bit — Compact) (IQ4_XS) 237.76 GiB 1.94 GiB 240.27 GiB (257.99 GB) ~4.1 tok/s Exceeds Available GPU Memory Instinct MI355X 288GB (288GB) Config-derived formula
GGUF Q3_K_M (3-bit — Low VRAM) (Q3_K_M) 218.73 GiB 1.94 GiB 221.24 GiB (237.55 GB) ~4.6 tok/s Exceeds Available GPU Memory Instinct MI325X 256GB (256GB) Config-derived formula
GGUF UD-Q2_K_XL (2-bit — Extreme MoE) (UD-Q2_K_XL) 154.05 GiB 1.94 GiB 156.56 GiB (168.11 GB) ~8.2 tok/s Exceeds Available GPU Memory Instinct MI300X 192GB (192GB) Config-derived formula

Technical Specifications & FAQ

Does Qwen3 Coder 480B-A35B fit on H100 80GB SXM (80GB)?

In 4-bit (Q4_K_M) at 8,192 context, Qwen3 Coder 480B-A35B requires 273.9 GiB total GPU memory (271.39 GiB weights + 1.94 GiB KV cache + 0.57 GiB runtime buffers) against 76 GiB usable on H100 80GB SXM, delivering ~3.4 tok/s decode.

How much VRAM does Qwen3 Coder 480B-A35B need at 32K context?

At 32,768 context tokens, Qwen3 Coder 480B-A35B (Sparse MoE + GQA) allocates 7.75 GiB for KV cache and state, bringing total 4-bit VRAM to 279.71 GiB (300.34 GB decimal).

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