Gemma 3 4B IT on Ryzen AI Max+ 395 128GB (128GB) — VRAM, KV Cache & Throughput
Gemma 3 4B IT (4.3B total, 4.3B active, Dense GQA) uses 2.7 GiB of 4-bit weights (Q4_K_M), requiring 3.56 GiB total at 8K context and 4.12 GiB at 32K on Ryzen AI Max+ 395 128GB (~59.7 tok/s decode).
Recommended Hardware for Current Configuration
Production Launch Commands
llama-server -hf unsloth/gemma-3-4b-it-GGUF:Q4_K_M \ --ctx-size 8192 -ngl 999 --flash-attn
vllm serve google/gemma-3-4b-it \ --max-model-len 8192 --gpu-memory-utilization 0.92
Cloud GPU Comparison & Rent-vs-Buy TCO
Verified public rates across RunPod, Vast.ai, Vultr, and DigitalOcean.
| Provider | Recommended Instance | Total VRAM | Hourly Rate | Monthly at Selected Hours | Billing Mode | Deploy |
|---|---|---|---|---|---|---|
| RunPod | 1x RTX 5060 Ti 16GB (Community Cloud) | 16 GB | $0.18 / hr | $21.89 / 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) — Gemma 3 4B IT
Engineering Sizing Notes & Optimization Playbook
Quick Hardware Verdict
Ryzen AI Max+ 395 128GB (128GB physical, 99.8 GiB usable) runs 4-bit (Q4_K_M) Gemma 3 4B IT at 8K context using 3.56 GiB with 96.24 GiB of safe headroom (~59.7 tok/s single-stream decode).
KV Cache & Runtime Tuning
Gemma 3 4B IT uses Dense GQA (4.3B total, 4.3B active per token). Moving from 8K to 32K context expands FP16 KV cache from 0.3 GiB to 0.86 GiB; enabling 8-bit KV cache (llama.cpp -ctk q8_0 -ctv q8_0 or vLLM --kv-cache-dtype fp8) saves 0.43 GiB at 32K (reducing total VRAM to 3.69 GiB).
VRAM Scaling Across Context Windows (4K to 128K, 4-bit Weights)
Quantization Precision & Memory Matrix — Gemma 3 4B IT @ 8K
| Quantization Format | Weights (GiB) | KV Cache | Total VRAM (GiB) | Decode Speed | Compatibility (Ryzen AI Max+ 395 128GB) | Recommended GPU | Data Source |
|---|---|---|---|---|---|---|---|
| Native Weights (BF16 / FP8 / MXFP4 — Lossless) (BF16) | 8.01 GiB | 0.3 GiB | 8.87 GiB (9.52 GB) | ~21.2 tok/s | Fits with Safe Headroom | RTX 4060 Ti 16GB (16GB) | Official checkpoint size |
| FP8 / GGUF Q8_0 (8-bit — Near-Lossless) (Q8_0) | 4.25 GiB | 0.3 GiB | 5.11 GiB (5.49 GB) | ~39 tok/s | Fits with Safe Headroom | RTX 4060 Ti 16GB (16GB) | Config-derived formula |
| GGUF Q6_K (6-bit — High Precision) (Q6_K) | 3.28 GiB | 0.3 GiB | 4.14 GiB (4.45 GB) | ~49.8 tok/s | Fits with Safe Headroom | RTX 4060 Ti 16GB (16GB) | Config-derived formula |
| GGUF Q5_K_M (5-bit — Balanced) (Q5_K_M) | 2.98 GiB | 0.3 GiB | 3.84 GiB (4.12 GB) | ~54.5 tok/s | Fits with Safe Headroom | RTX 4060 Ti 16GB (16GB) | Config-derived formula |
| Q4_K_M / UD-Q4_K_XL / AWQ (4-bit — Recommended) (Q4_K_M) | 2.7 GiB | 0.3 GiB | 3.56 GiB (3.82 GB) | ~59.7 tok/s | Fits with Safe Headroom | RTX 4060 Ti 16GB (16GB) | Config-derived formula |
| GGUF IQ4_XS (4.25-bit — Compact) (IQ4_XS) | 2.32 GiB | 0.3 GiB | 3.18 GiB (3.41 GB) | ~68.7 tok/s | Fits with Safe Headroom | RTX 4060 Ti 16GB (16GB) | Config-derived formula |
| GGUF Q3_K_M (3-bit — Low VRAM) (Q3_K_M) | 2.13 GiB | 0.3 GiB | 2.99 GiB (3.21 GB) | ~74.3 tok/s | Fits with Safe Headroom | RTX 4060 Ti 16GB (16GB) | Config-derived formula |
| GGUF UD-Q2_K_XL (2-bit — Extreme MoE) (UD-Q2_K_XL) | 1.65 GiB | 0.3 GiB | 2.51 GiB (2.7 GB) | ~93.4 tok/s | Fits with Safe Headroom | RTX 4060 Ti 16GB (16GB) | Config-derived formula |
Technical Specifications & FAQ
Does Gemma 3 4B IT fit on Ryzen AI Max+ 395 128GB (128GB)?
In 4-bit (Q4_K_M) at 8,192 context, Gemma 3 4B IT requires 3.56 GiB total GPU memory (2.7 GiB weights + 0.3 GiB KV cache + 0.56 GiB runtime buffers) against 99.8 GiB usable on Ryzen AI Max+ 395 128GB, delivering ~59.7 tok/s decode.
How much VRAM does Gemma 3 4B IT need at 32K context?
At 32,768 context tokens, Gemma 3 4B IT (Dense GQA) allocates 0.86 GiB for KV cache and state, bringing total 4-bit VRAM to 4.12 GiB (4.42 GB decimal).