Qwen3 4B Instruct 2507 VRAM Requirements, KV Cache & Best GPUs
Qwen3 4B Instruct 2507 (4.02B total, 4.02B active, Dense GQA) uses 2.33 GiB for 4-bit weights (Q4_K_M), requiring 4.02 GiB at 8K context and 7.39 GiB at 32K. · Hugging Face: Qwen/Qwen3-4B-Instruct-2507 ↗ · GGUF: unsloth/Qwen3-4B-Instruct-2507-GGUF ↗
Fits with Safe Headroom
Measured GGUF shard size
HF config.json ↗
Required GPU Memory
4.02 GiB
4.32 GB (decimal)
Usable Hardware Memory
15.2 GiB
16 GB (physical)
Safe Headroom
+11.18 GiB
25% utilization
Est. Decode Throughput
~64.8 tok/s
4.02B active params
Est. Prefill Throughput
~2846 tok/s
4K Prompt TTFT: ~1439 ms
Est. Cost / 1M Tokens
$0.26
Dense GQA · Apache-2.0
Recommended Hardware for Current Configuration
Best Single GPU
RTX 4060 Ti 16GB (16GB)
~$430
Best Value / Used GPU
RTX 3060 12GB (12GB)
~$280
Apple Unified Memory
Ryzen AI Max+ 395 128GB
~$1,999
Cloud From
Vast.ai · $0.06 / hr
1x RTX 3060 12GB
Production Launch Commands
llama.cpp (GGUF)
llama-server -hf unsloth/Qwen3-4B-Instruct-2507-GGUF:Q4_K_M \ --ctx-size 8192 -ngl 999 --flash-attn
vLLM
vllm serve Qwen/Qwen3-4B-Instruct-2507 \ --max-model-len 8192 --gpu-memory-utilization 0.92
Live Token Speed Simulator (TTFT ~1439ms · ~64.8 tok/s)
[Qwen3 4B Instruct 2507 · 4.02 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.
Purchase break-even
~18.5 months
Est. local power: $3.51 / mo
| Provider | Recommended Instance | Total VRAM | Hourly Rate | Monthly at Selected Hours | Billing Mode | Deploy |
|---|---|---|---|---|---|---|
| RunPod | 1x RTX 3090 (Community Cloud) | 24 GB | $0.22 / hr | $26.75 / mo | Per-second | Deploy GPU ↗ |
| Vast.ai | 1x RTX 3060 12GB (Verified Host) | 12 GB | $0.06 / hr | $7.42 / mo | Spot / On-demand | Deploy GPU ↗ |
| Vultr ($300 Free Credit*) | 1x L40S 48GB (Dedicated Instance · $300 Credit*) | 48 GB | $1.67 / hr | $203.19 / mo | Hourly | Deploy GPU ↗ |
| Vultr Cloud GPU | 1x L40S 48GB (Dedicated Instance) | 48 GB | $1.67 / hr | $203.19 / mo | Hourly | Deploy GPU ↗ |
| DigitalOcean | 1x RTX 6000 Ada (Dedicated Instance) | 48 GB | $1.57 / hr | $190.91 / 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 4B Instruct 2507
QLoRA (4b)
Fits with Safe Headroom
4.56 GiB
Model Weights: 2.33 GiB · Gradients + Optimizer: 1.2 GiB · Act: 1.03 GiB
Recommended GPU: RTX 4060 Ti 16GB (16GB)
LoRA (16b)
Fits with Safe Headroom
10.65 GiB
Model Weights: 7.49 GiB · Gradients + Optimizer: 1.8 GiB · Act: 1.36 GiB
Recommended GPU: RTX 4060 Ti 16GB (16GB)
Full BF16
Exceeds Available GPU Memory
33.11 GiB
Model Weights: 7.49 GiB · Gradients + Optimizer: 23.22 GiB · Act: 2.4 GiB
Recommended GPU: A40 48GB (48GB)
Engineering Sizing Notes & Optimization Playbook
Quick Hardware Verdict
RTX 4060 Ti 16GB (16GB physical, 15.2 GiB usable) runs 4-bit (Q4_K_M) Qwen3 4B Instruct 2507 at 8K context using 4.02 GiB with 11.18 GiB of safe headroom (~64.8 tok/s single-stream decode).
KV Cache & Runtime Tuning
Qwen3 4B Instruct 2507 uses Dense GQA (4.02B total, 4.02B active per token). Moving from 8K to 32K context expands FP16 KV cache from 1.13 GiB to 4.5 GiB; enabling 8-bit KV cache (llama.cpp -ctk q8_0 -ctv q8_0 or vLLM --kv-cache-dtype fp8) saves 2.25 GiB at 32K (reducing total VRAM to 5.14 GiB).
VRAM Scaling Across Context Windows (4K to 128K, 4-bit Weights)
Qwen3 4B Instruct 2507 × 49 GPUs (4-bit Q4_K_M)
| Target Hardware | Total VRAM | Memory Bandwidth | 4-bit @ 8K | 4-bit @ 32K | Decode Speed | Compatibility | Full Compatibility Report |
|---|---|---|---|---|---|---|---|
| NVIDIA RTX 3060 12GB | 12 GB (11.4 GiB) | 360 GB/s | 4.02 GiB | 7.39 GiB | ~80 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX 4060 Ti 16GB | 16 GB (15.2 GiB) | 288 GB/s | 4.02 GiB | 7.39 GiB | ~64.8 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX 4070 Ti Super | 16 GB (15.2 GiB) | 672 GB/s | 4.02 GiB | 7.39 GiB | ~141.4 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX 4080 Super | 16 GB (15.2 GiB) | 736 GB/s | 4.02 GiB | 7.39 GiB | ~153.3 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX 5070 12GB | 12 GB (11.4 GiB) | 672 GB/s | 4.02 GiB | 7.39 GiB | ~141.4 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX 5070 Ti | 16 GB (15.2 GiB) | 896 GB/s | 4.02 GiB | 7.39 GiB | ~181.7 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX 5080 | 16 GB (15.2 GiB) | 960 GB/s | 4.02 GiB | 7.39 GiB | ~192.7 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX 3090 | 24 GB (22.8 GiB) | 936 GB/s | 4.02 GiB | 7.39 GiB | ~188.6 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX 4090 | 24 GB (22.8 GiB) | 1008 GB/s | 4.02 GiB | 7.39 GiB | ~200.8 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX 4090 D | 24 GB (22.8 GiB) | 1008 GB/s | 4.02 GiB | 7.39 GiB | ~200.8 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX 5090 | 32 GB (30.4 GiB) | 1792 GB/s | 4.02 GiB | 7.39 GiB | ~317.3 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX 5090 D | 32 GB (30.4 GiB) | 1792 GB/s | 4.02 GiB | 7.39 GiB | ~317.3 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX A6000 | 48 GB (45.6 GiB) | 768 GB/s | 4.02 GiB | 7.39 GiB | ~159.1 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX 6000 Ada | 48 GB (45.6 GiB) | 960 GB/s | 4.02 GiB | 7.39 GiB | ~192.7 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA RTX PRO 6000 Blackwell | 96 GB (91.2 GiB) | 1792 GB/s | 4.02 GiB | 7.39 GiB | ~317.3 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA DGX Spark (GB10 128GB) | 128 GB (99.8 GiB) | 273 GB/s | 4.02 GiB | 7.39 GiB | ~67.2 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA L4 24GB | 24 GB (22.8 GiB) | 300 GB/s | 4.02 GiB | 7.39 GiB | ~67.4 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA A40 48GB | 48 GB (45.6 GiB) | 696 GB/s | 4.02 GiB | 7.39 GiB | ~145.9 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA L20 48GB | 48 GB (45.6 GiB) | 864 GB/s | 4.02 GiB | 7.39 GiB | ~176.2 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA L40S 48GB | 48 GB (45.6 GiB) | 864 GB/s | 4.02 GiB | 7.39 GiB | ~176.2 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA A800 80GB SXM | 80 GB (76 GiB) | 2039 GB/s | 4.02 GiB | 7.39 GiB | ~348.9 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA A100 80GB SXM | 80 GB (76 GiB) | 2039 GB/s | 4.02 GiB | 7.39 GiB | ~348.9 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA H800 80GB SXM | 80 GB (76 GiB) | 3350 GB/s | 4.02 GiB | 7.39 GiB | ~380 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA H100 80GB SXM | 80 GB (76 GiB) | 3350 GB/s | 4.02 GiB | 7.39 GiB | ~380 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA H20 96GB HBM3 | 96 GB (91.2 GiB) | 4000 GB/s | 4.02 GiB | 7.39 GiB | ~380 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA H20 141GB HBM3e | 141 GB (133.9 GiB) | 4800 GB/s | 4.02 GiB | 7.39 GiB | ~380 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA H200 141GB SXM | 141 GB (133.9 GiB) | 4800 GB/s | 4.02 GiB | 7.39 GiB | ~380 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA B200 180GB | 180 GB (171 GiB) | 8000 GB/s | 4.02 GiB | 7.39 GiB | ~380 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| NVIDIA B300 288GB Blackwell Ultra | 288 GB (273.6 GiB) | 8000 GB/s | 4.02 GiB | 7.39 GiB | ~380 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| Huawei Ascend 910B 64GB (昇腾) | 64 GB (60.8 GiB) | 1200 GB/s | 4.02 GiB | 7.39 GiB | ~231.9 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| Huawei Ascend 910C 128GB (昇腾) | 128 GB (121.6 GiB) | 2400 GB/s | 4.02 GiB | 7.39 GiB | ~380 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| Huawei Atlas 300I Duo 96GB (310P) | 96 GB (91.2 GiB) | 408 GB/s | 4.02 GiB | 7.39 GiB | ~89.9 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| Cambricon MLU590 80GB (寒武纪思元) | 80 GB (76 GiB) | 2048 GB/s | 4.02 GiB | 7.39 GiB | ~350 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| Hygon DCU K100-AI 64GB (海光深算) | 64 GB (60.8 GiB) | 1638 GB/s | 4.02 GiB | 7.39 GiB | ~296.5 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| MetaX MetaX C500 64GB (沐曦曦云) | 64 GB (60.8 GiB) | 1800 GB/s | 4.02 GiB | 7.39 GiB | ~318.4 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| Kunlunxin Kunlunxin P800 64GB (昆仑芯) | 64 GB (60.8 GiB) | 1600 GB/s | 4.02 GiB | 7.39 GiB | ~291.2 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| Moore Threads MTT S4000 48GB (摩尔线程) | 48 GB (45.6 GiB) | 768 GB/s | 4.02 GiB | 7.39 GiB | ~159.1 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| AMD Radeon RX 7900 XTX 24GB | 24 GB (22.8 GiB) | 960 GB/s | 4.02 GiB | 7.39 GiB | ~192.7 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| AMD Radeon AI PRO R9700 32GB | 32 GB (30.4 GiB) | 640 GB/s | 4.02 GiB | 7.39 GiB | ~135.4 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| AMD Ryzen AI Max+ 395 128GB | 128 GB (99.8 GiB) | 256 GB/s | 4.02 GiB | 7.39 GiB | ~63.3 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| AMD Instinct MI300X 192GB | 192 GB (182.4 GiB) | 5300 GB/s | 4.02 GiB | 7.39 GiB | ~380 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| AMD Instinct MI325X 256GB | 256 GB (243.2 GiB) | 6000 GB/s | 4.02 GiB | 7.39 GiB | ~380 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| AMD Instinct MI355X 288GB | 288 GB (273.6 GiB) | 8000 GB/s | 4.02 GiB | 7.39 GiB | ~380 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| Intel Arc Pro B60 24GB | 24 GB (22.8 GiB) | 456 GB/s | 4.02 GiB | 7.39 GiB | ~99.6 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| Intel Gaudi 3 128GB HBM2e | 128 GB (121.6 GiB) | 3700 GB/s | 4.02 GiB | 7.39 GiB | ~380 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| Apple Mac mini M4 Pro 64GB | 64 GB (49.9 GiB) | 273 GB/s | 4.02 GiB | 7.39 GiB | ~67.2 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| Apple MacBook Pro M4 Max 128GB | 128 GB (99.8 GiB) | 546 GB/s | 4.02 GiB | 7.39 GiB | ~127.6 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| Apple Mac Studio M4 Ultra 256GB | 256 GB (199.7 GiB) | 819 GB/s | 4.02 GiB | 7.39 GiB | ~182.1 tok/s | Fits with Safe Headroom | Full Compatibility Report → |
| Apple Mac Studio M3 Ultra 512GB | 512 GB (399.4 GiB) | 819 GB/s | 4.02 GiB | 7.39 GiB | ~182.1 tok/s | Fits with Safe Headroom | Full Compatibility Report → |