Qwen3 Coder Next 80B-A3B on Radeon RX 7900 XTX 24GB (24GB) — VRAM, KV Cache & Throughput

Qwen3 Coder Next 80B-A3B (79.67B total, 3B active, Hybrid Linear/Mamba + MoE) uses 45.2 GiB of 4-bit weights (Q4_K_M), requiring 46.02 GiB total at 8K context and 46.58 GiB at 32K on Radeon RX 7900 XTX 24GB (~38.2 tok/s decode).

Interactive Sizing Workbench

Full Compatibility Report →
24 GB · 960 GB/s
Exceeds Available GPU Memory
Measured GGUF shard size HF config.json ↗
Memory Allocation Breakdown (GiB) 46.02 GiB (49.41 GB) / 24 GiB (192%)
Model Weights: 45.2 GiB KV Cache & State: 0.26 GiB Runtime & Activation Buffers: 0.56 GiB System RAM Offload: 0 GiB
Required GPU Memory
46.02 GiB
49.41 GB (decimal)
Usable Hardware Memory
22.8 GiB
24 GB (physical)
Safe Headroom
-23.22 GiB
192% utilization
Est. Decode Throughput
~38.2 tok/s
3B active params
Est. Prefill Throughput
~10660 tok/s
4K Prompt TTFT: ~384 ms
Est. Cost / 1M Tokens
$3.21
Hybrid Linear/Mamba + MoE · Apache-2.0

Recommended Hardware for Current Configuration

Best Single GPU
RTX PRO 6000 Blackwell (96GB)
~$8,500
Best Value / Used GPU
2x RTX 5090
64GB · ~$5,200
Apple Unified Memory
Ryzen AI Max+ 395 128GB
~$1,999
Cloud From
Vast.ai · $0.44 / hr
1x A100 80GB SXM

Production Launch Commands

llama.cpp (GGUF)
llama-server -hf unsloth/Qwen3-Coder-Next-GGUF:Q4_K_M \
  --ctx-size 8192 -ngl 999 --flash-attn
vLLM
vllm serve Qwen/Qwen3-Coder-Next \
  --max-model-len 8192 --gpu-memory-utilization 0.92
Live Token Speed Simulator (TTFT ~384ms · ~38.2 tok/s)
[Qwen3 Coder Next 80B-A3B · 46.02 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
~64.4 months
Est. local power: $12.77 / mo
Provider Recommended Instance Total VRAM Hourly Rate Monthly at Selected Hours Billing Mode Deploy
RunPod 1x A100 80GB SXM (Community Cloud · PCIe) 80 GB $1.19 / hr $144.70 / mo Per-second Deploy GPU ↗
Vast.ai 1x A100 80GB SXM (Verified Host · SXM4) 80 GB $0.44 / hr $53.75 / mo Spot / On-demand Deploy GPU ↗
Vultr ($300 Free Credit*) 1x A100 80GB SXM (Dedicated Instance · $300 Credit*) 80 GB $2.40 / hr $291.48 / mo Hourly Deploy GPU ↗
Vultr Cloud GPU 1x A100 80GB SXM (Dedicated Instance) 80 GB $2.40 / hr $291.48 / mo Hourly Deploy GPU ↗
DigitalOcean 1x Instinct MI300X 192GB (Dedicated Instance) 192 GB $2.59 / hr $314.94 / 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 Next 80B-A3B

QLoRA (4b) Exceeds Available GPU Memory
47.41 GiB
Model Weights: 45.2 GiB · Gradients + Optimizer: 1.2 GiB · Act: 1.01 GiB
Recommended GPU: RTX PRO 6000 Blackwell (96GB)
LoRA (16b) Exceeds Available GPU Memory
151.54 GiB
Model Weights: 148.4 GiB · Gradients + Optimizer: 1.8 GiB · Act: 1.34 GiB
Recommended GPU: Instinct MI300X 192GB (192GB)
Full BF16 Exceeds Available GPU Memory
610.8 GiB
Model Weights: 148.4 GiB · Gradients + Optimizer: 460.04 GiB · Act: 2.36 GiB
Recommended GPU: 4x B200 180GB (720GB)

Engineering Sizing Notes & Optimization Playbook

Quick Hardware Verdict

A single Radeon RX 7900 XTX 24GB (24GB) cannot hold 4-bit Qwen3 Coder Next 80B-A3B (46.02 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 Next 80B-A3B uses Hybrid Linear/Mamba + MoE (79.67B total, 3B active per token). Moving from 8K to 32K context expands FP16 KV cache from 0.26 GiB to 0.82 GiB; enabling 8-bit KV cache (llama.cpp -ctk q8_0 -ctv q8_0 or vLLM --kv-cache-dtype fp8) saves 0.37 GiB at 32K (reducing total VRAM to 46.21 GiB).

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

Qwen3 Coder Next 80B-A3B VRAM scaling from 4K to 128K context (4K: 45.92 GiB, 8K: 46.02 GiB, 32K: 46.58 GiB, 128K: 48.83 GiB) 4K 45.92 GiB (KV 0.17 GiB) 8K 46.02 GiB (KV 0.26 GiB) 32K 46.58 GiB (KV 0.82 GiB) 128K 48.83 GiB (KV 3.07 GiB) Radeon RX 7900 XTX 24GB (24GB)
Model weights remain constant while attention KV cache grows with context length and batch size.

Quantization Precision & Memory Matrix — Qwen3 Coder Next 80B-A3B @ 8K

Quantization Format Weights (GiB) KV Cache Total VRAM (GiB) Decode Speed Compatibility (Radeon RX 7900 XTX 24GB) Recommended GPU Data Source
Native Weights (BF16 / FP8 / MXFP4 — Lossless) (BF16) 148.4 GiB 0.26 GiB 149.22 GiB (160.22 GB) ~9.5 tok/s Exceeds Available GPU Memory Instinct MI300X 192GB (192GB) Official checkpoint size
FP8 / GGUF Q8_0 (8-bit — Near-Lossless) (Q8_0) 78.99 GiB 0.26 GiB 79.81 GiB (85.7 GB) ~18.7 tok/s Exceeds Available GPU Memory RTX PRO 6000 Blackwell (96GB) Measured GGUF shard size
GGUF Q6_K (6-bit — High Precision) (Q6_K) 61.11 GiB 0.26 GiB 61.93 GiB (66.5 GB) ~25.4 tok/s Exceeds Available GPU Memory RTX PRO 6000 Blackwell (96GB) Measured GGUF shard size
GGUF Q5_K_M (5-bit — Balanced) (Q5_K_M) 52.94 GiB 0.26 GiB 53.76 GiB (57.72 GB) ~30.5 tok/s Exceeds Available GPU Memory RTX PRO 6000 Blackwell (96GB) Measured GGUF shard size
Q4_K_M / UD-Q4_K_XL / AWQ (4-bit — Recommended) (Q4_K_M) 45.2 GiB 0.26 GiB 46.02 GiB (49.41 GB) ~38.2 tok/s Exceeds Available GPU Memory RTX PRO 6000 Blackwell (96GB) Measured GGUF shard size
GGUF IQ4_XS (4.25-bit — Compact) (IQ4_XS) 35.79 GiB 0.26 GiB 36.61 GiB (39.31 GB) ~56.5 tok/s Exceeds Available GPU Memory A40 48GB (48GB) Measured GGUF shard size
GGUF Q3_K_M (3-bit — Low VRAM) (Q3_K_M) 33.47 GiB 0.26 GiB 34.29 GiB (36.82 GB) ~64.7 tok/s Exceeds Available GPU Memory A40 48GB (48GB) Measured GGUF shard size
GGUF UD-Q2_K_XL (2-bit — Extreme MoE) (UD-Q2_K_XL) 24.92 GiB 0.26 GiB 25.74 GiB (27.64 GB) ~158 tok/s Exceeds Available GPU Memory Radeon AI PRO R9700 32GB (32GB) Measured GGUF shard size

Technical Specifications & FAQ

Does Qwen3 Coder Next 80B-A3B fit on Radeon RX 7900 XTX 24GB (24GB)?

In 4-bit (Q4_K_M) at 8,192 context, Qwen3 Coder Next 80B-A3B requires 46.02 GiB total GPU memory (45.2 GiB weights + 0.26 GiB KV cache + 0.56 GiB runtime buffers) against 22.8 GiB usable on Radeon RX 7900 XTX 24GB, delivering ~38.2 tok/s decode.

How much VRAM does Qwen3 Coder Next 80B-A3B need at 32K context?

At 32,768 context tokens, Qwen3 Coder Next 80B-A3B (Hybrid Linear/Mamba + MoE) allocates 0.82 GiB for KV cache and state, bringing total 4-bit VRAM to 46.58 GiB (50.01 GB decimal).

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