Gemma 4 26B-A4B IT on RTX A6000 (48GB) — VRAM, KV Cache & Throughput
Gemma 4 26B-A4B IT (25.81B total, 3.8B active, Sparse MoE + GQA) uses 15.84 GiB of 4-bit weights (UD-Q4_K_XL), requiring 16.75 GiB total at 8K context and 17.22 GiB at 32K on RTX A6000 (~114.7 tok/s decode).
Recommended Hardware for Current Configuration
Production Launch Commands
llama-server -hf unsloth/gemma-4-26B-A4B-it-GGUF:UD-Q4_K_XL \ --ctx-size 8192 -ngl 999 --flash-attn
vllm serve google/gemma-4-26B-A4B-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 3090 (Community Cloud) | 24 GB | $0.22 / hr | $26.75 / mo | Per-second | Deploy GPU ↗ |
| Vast.ai | 1x RTX 3090 (Verified Host) | 24 GB | $0.19 / hr | $22.98 / 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 4 26B-A4B IT
Engineering Sizing Notes & Optimization Playbook
Quick Hardware Verdict
RTX A6000 (48GB physical, 45.6 GiB usable) runs 4-bit (UD-Q4_K_XL) Gemma 4 26B-A4B IT at 8K context using 16.75 GiB with 28.85 GiB of safe headroom (~114.7 tok/s single-stream decode).
KV Cache & Runtime Tuning
Gemma 4 26B-A4B IT uses Sparse MoE + GQA (25.81B total, 3.8B active per token). Moving from 8K to 32K context expands FP16 KV cache from 0.35 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 0.41 GiB at 32K (reducing total VRAM to 16.81 GiB).
VRAM Scaling Across Context Windows (4K to 128K, 4-bit Weights)
Quantization Precision & Memory Matrix — Gemma 4 26B-A4B IT @ 8K
| Quantization Format | Weights (GiB) | KV Cache | Total VRAM (GiB) | Decode Speed | Compatibility (RTX A6000) | Recommended GPU | Data Source |
|---|---|---|---|---|---|---|---|
| Native Weights (BF16 / FP8 / MXFP4 — Lossless) (BF16) | 48.07 GiB | 0.35 GiB | 48.98 GiB (52.59 GB) | ~41.5 tok/s | Exceeds Available GPU Memory | RTX PRO 6000 Blackwell (96GB) | Official checkpoint size |
| FP8 / GGUF Q8_0 (8-bit — Near-Lossless) (Q8_0) | 25.54 GiB | 0.35 GiB | 26.45 GiB (28.4 GB) | ~79.6 tok/s | Fits with Safe Headroom | Radeon AI PRO R9700 32GB (32GB) | Config-derived formula |
| GGUF Q6_K (6-bit — High Precision) (Q6_K) | 21.58 GiB | 0.35 GiB | 22.49 GiB (24.15 GB) | ~91 tok/s | Fits with Safe Headroom | Radeon AI PRO R9700 32GB (32GB) | Measured GGUF shard size |
| GGUF Q5_K_M (5-bit — Balanced) (Q5_K_M) | 19.7 GiB | 0.35 GiB | 20.61 GiB (22.13 GB) | ~97.6 tok/s | Fits with Safe Headroom | Arc Pro B60 24GB (24GB) | Measured GGUF shard size |
| Q4_K_M / UD-Q4_K_XL / AWQ (4-bit — Recommended) (UD-Q4_K_XL) | 15.84 GiB | 0.35 GiB | 16.75 GiB (17.99 GB) | ~114.7 tok/s | Fits with Safe Headroom | Arc Pro B60 24GB (24GB) | Measured GGUF shard size |
| GGUF IQ4_XS (4.25-bit — Compact) (IQ4_XS) | 12.66 GiB | 0.35 GiB | 13.57 GiB (14.57 GB) | ~134.2 tok/s | Fits with Safe Headroom | RTX 4060 Ti 16GB (16GB) | Measured GGUF shard size |
| GGUF Q3_K_M (3-bit — Low VRAM) (Q3_K_M) | 11.85 GiB | 0.35 GiB | 12.76 GiB (13.7 GB) | ~140.2 tok/s | Fits with Safe Headroom | RTX 4060 Ti 16GB (16GB) | Measured GGUF shard size |
| GGUF UD-Q2_K_XL (2-bit — Extreme MoE) (UD-Q2_K_XL) | 9.82 GiB | 0.35 GiB | 10.73 GiB (11.52 GB) | ~158 tok/s | Fits with Safe Headroom | RTX 4060 Ti 16GB (16GB) | Measured GGUF shard size |
Technical Specifications & FAQ
Does Gemma 4 26B-A4B IT fit on RTX A6000 (48GB)?
In 4-bit (UD-Q4_K_XL) at 8,192 context, Gemma 4 26B-A4B IT requires 16.75 GiB total GPU memory (15.84 GiB weights + 0.35 GiB KV cache + 0.56 GiB runtime buffers) against 45.6 GiB usable on RTX A6000, delivering ~114.7 tok/s decode.
How much VRAM does Gemma 4 26B-A4B IT need at 32K context?
At 32,768 context tokens, Gemma 4 26B-A4B IT (Sparse MoE + GQA) allocates 0.82 GiB for KV cache and state, bringing total 4-bit VRAM to 17.22 GiB (18.49 GB decimal).