Devstral Small 24B on RTX 4070 Ti Super (16GB) — VRAM, KV Cache & Throughput
Devstral Small 24B (23.6B total, 23.6B active, Dense GQA) uses 13.59 GiB of 4-bit weights (Q4_K_M), requiring 15.4 GiB total at 8K context and 19.15 GiB at 32K on RTX 4070 Ti Super (~29.3 tok/s decode).
Recommended Hardware for Current Configuration
Production Launch Commands
llama-server -hf unsloth/Devstral-Small-2505-GGUF:Q4_K_M \ --ctx-size 8192 -ngl 999 --flash-attn
vllm serve mistralai/Devstral-Small-2505 \ --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) — Devstral Small 24B
Engineering Sizing Notes & Optimization Playbook
Quick Hardware Verdict
A single RTX 4070 Ti Super (16GB) cannot hold 4-bit Devstral Small 24B (15.4 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
Devstral Small 24B uses Dense GQA (23.6B total, 23.6B active per token). Moving from 8K to 32K context expands FP16 KV cache from 1.25 GiB to 5 GiB; enabling 8-bit KV cache (llama.cpp -ctk q8_0 -ctv q8_0 or vLLM --kv-cache-dtype fp8) saves 2.5 GiB at 32K (reducing total VRAM to 16.65 GiB).
VRAM Scaling Across Context Windows (4K to 128K, 4-bit Weights)
Quantization Precision & Memory Matrix — Devstral Small 24B @ 8K
| Quantization Format | Weights (GiB) | KV Cache | Total VRAM (GiB) | Decode Speed | Compatibility (RTX 4070 Ti Super) | Recommended GPU | Data Source |
|---|---|---|---|---|---|---|---|
| Native Weights (BF16 / FP8 / MXFP4 — Lossless) (BF16) | 43.96 GiB | 1.25 GiB | 45.77 GiB (49.15 GB) | ~1.7 tok/s | Exceeds Available GPU Memory | RTX PRO 6000 Blackwell (96GB) | Official checkpoint size |
| FP8 / GGUF Q8_0 (8-bit — Near-Lossless) (Q8_0) | 23.35 GiB | 1.25 GiB | 25.16 GiB (27.02 GB) | ~4.8 tok/s | Exceeds Available GPU Memory | Radeon AI PRO R9700 32GB (32GB) | Config-derived formula |
| GGUF Q6_K (6-bit — High Precision) (Q6_K) | 18.02 GiB | 1.25 GiB | 19.83 GiB (21.29 GB) | ~9.4 tok/s | Exceeds Available GPU Memory | Arc Pro B60 24GB (24GB) | Config-derived formula |
| GGUF Q5_K_M (5-bit — Balanced) (Q5_K_M) | 15.77 GiB | 1.25 GiB | 17.58 GiB (18.88 GB) | ~15.4 tok/s | Exceeds Available GPU Memory | Arc Pro B60 24GB (24GB) | Config-derived formula |
| Q4_K_M / UD-Q4_K_XL / AWQ (4-bit — Recommended) (Q4_K_M) | 13.59 GiB | 1.25 GiB | 15.4 GiB (16.54 GB) | ~29.3 tok/s | Tight Fit (<8% Headroom) | Arc Pro B60 24GB (24GB) | Config-derived formula |
| GGUF IQ4_XS (4.25-bit — Compact) (IQ4_XS) | 11.87 GiB | 1.25 GiB | 13.68 GiB (14.69 GB) | ~33.3 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) | 10.91 GiB | 1.25 GiB | 12.72 GiB (13.66 GB) | ~36.1 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) | 7.83 GiB | 1.25 GiB | 9.64 GiB (10.35 GB) | ~49.2 tok/s | Fits with Safe Headroom | RTX 4060 Ti 16GB (16GB) | Config-derived formula |
Technical Specifications & FAQ
Does Devstral Small 24B fit on RTX 4070 Ti Super (16GB)?
In 4-bit (Q4_K_M) at 8,192 context, Devstral Small 24B requires 15.4 GiB total GPU memory (13.59 GiB weights + 1.25 GiB KV cache + 0.56 GiB runtime buffers) against 15.2 GiB usable on RTX 4070 Ti Super, delivering ~29.3 tok/s decode.
How much VRAM does Devstral Small 24B need at 32K context?
At 32,768 context tokens, Devstral Small 24B (Dense GQA) allocates 5 GiB for KV cache and state, bringing total 4-bit VRAM to 19.15 GiB (20.56 GB decimal).