Buying Guide

Best GPUs for Stable Diffusion, Flux, and SD3 in 2026

GPU requirements for SDXL, Stable Diffusion 3 Medium, SD 3.5 Large, and FLUX.1 Dev. Per-GPU performance verdicts for RTX 4060 Ti, RTX 4070, RTX 4090, and Apple Silicon.

OwnRig Editorial|11 min read|April 18, 2026

Image generation has a more complicated VRAM story than language models. Language models just need weights to fit; image generation adds a denoising loop, a VAE, and a text encoder, all running simultaneously. The VRAM math compounds.

And the model landscape shifted significantly in 2025 and 2026. FLUX.1 Dev changed the benchmark for local image quality, but it comes with steep VRAM requirements. SD 3 and SD 3.5 occupy the middle ground. SDXL is still surprisingly capable on budget hardware. Here's how each model maps to actual consumer GPUs.

01

The image gen model landscape in 2026

Four models are worth benchmarking against your hardware right now. Here's the baseline VRAM picture:

ModelFP16 VRAMQ8_0 VRAMQ4_K_M VRAMBest for
Stable Diffusion XL 1.06.5 GBN/AN/AFast, versatile 1024px generation
Stable Diffusion 3 Medium5 GBN/AN/AHigh coherence, great text rendering
Stable Diffusion 3.5 Large12.5 GB9 GBN/ABest SD3 quality; photorealism
FLUX.1 Dev23.8 GB13 GB7.2 GBTop-tier quality; detail and realism

SDXL and SD3 Medium are the accessible ones. Both run at FP16 on 8 GB cards. FLUX.1 Dev is where the VRAM conversation gets serious.

02

SDXL and SD3 Medium: the 8 GB tier

If you own an RTX 4060, RTX 3070, or any card with 8 to 12 GB of VRAM, SDXL and Stable Diffusion 3 Medium are your primary image generation tools. Both run at full FP16 quality within 8 GB.

SDXL is fast, well-supported, and has the richest ecosystem of LoRAs and fine-tunes. SD3 Medium has better text rendering and prompt coherence. For general photorealistic images, SD3 Medium edges ahead. For artistic styles and specialized fine-tunes, SDXL's ecosystem wins.

5 GB

VRAM needed for Stable Diffusion 3 Medium at FP16

Runs on any GPU with 6 GB or more, including budget options

Neither model pushes consumer GPUs. A 12 GB card like the RTX 4070 Ti runs them with roughly 5 to 7 GB to spare, which means you can generate at higher resolutions or run larger batch sizes without hitting the VRAM wall.

03

FLUX.1 Dev: the demanding one

FLUX.1 Dev is the most capable open image generation model available in 2026, and it earns that title by demanding hardware. At FP16, it needs 23.8 GB. That's right at the edge of a 24 GB card.

The quantization options change the math significantly:

QuantizationVRAM neededFits inQuality impact
FP1623.8 GB24 GB-class discrete GPUs and upFull tier in our model data
Q8_013 GB16 GB cards on paper; verify exact runtime support per deviceRecommended tier in our model data
Q4_K_M7.2 GBRTX 4060 8 GB, any 8 GB cardEfficient tier in our model data
04

Per-GPU verdict

Every major consumer GPU in our database, with honest verdicts on what you can actually run:

GPUVRAMSDXLSD3 MediumFLUX.1 Dev
RTX 4060 8GB8 GBFull qualityFull qualityQ4 only (degraded)
RTX 4060 Ti 16GB16 GBFull qualityFull qualityQ4_K_M path in matrix
RTX 4070 Ti 12GB12 GBFull qualityFull qualityQ8_0 is not viable in matrix
RTX 409024 GBFull qualityFull qualityFP16 in matrix
05

Recommendations by budget

I'll be direct about what I'd buy at each price point.

Under $400: The RTX 4060 8 GB (about $289 in our device data) handles SDXL and SD3 Medium at full quality. For FLUX, you're stuck at Q4, which is workable but not ideal. If image generation is your main use, save up.

$400 to $500: The RTX 4060 Ti 16 GB is the right buy for SDXL, SD3 Medium, and SD3.5 Large. This is the recommended card for most image generation setups if FLUX FP16 is not the main goal.

$1,500 and up: An RTX 4090 at about $1,799 in our device data is the cleanest consumer path to FLUX.1 Dev at FP16. It gives you 24 GB of VRAM, full FLUX quality, and enough headroom to make high-res batch generation practical.

Common Questions
How much VRAM do I need for Stable Diffusion?
It depends on which model. SDXL runs at FP16 on 6.5 GB, so an 8 GB GPU handles it. Stable Diffusion 3 Medium needs 5 GB at FP16. FLUX.1 Dev is the demanding one: 23.8 GB at FP16. The Q4_K_M quantization brings Flux down to 7.2 GB, which fits on a 8 GB card, at some quality cost.
Can I run FLUX.1 Dev on an RTX 4060?
At FP16, no: FLUX.1 Dev needs 23.8 GB. But with Q4_K_M quantization, the requirement drops to 7.2 GB, which fits on an RTX 4060 8 GB. Our compatibility matrix marks that combination as a tight but viable fit, with quality and speed tradeoffs versus larger cards.
Is the RTX 4070 Ti good for Stable Diffusion?
The RTX 4070 Ti has 12 GB of VRAM. That handles SDXL and SD3 Medium comfortably at full quality, and it also supports Stable Diffusion 3.5 Large at Q8_0 in our compatibility matrix. For FLUX.1 Dev without compression or offloading, you want a 24 GB-class discrete GPU.
Does resolution affect VRAM requirements for image generation?
Yes. The VRAM numbers in our data are baseline figures for standard single-image generation. Higher resolutions and larger batch sizes push usage up, so treat these numbers as the floor, not the ceiling.
Can Apple Silicon run Stable Diffusion well?
Yes, especially for SDXL and Stable Diffusion 3.5 Large. Our compatibility matrix includes Apple Silicon entries for those models on M4 Pro-class devices. For FLUX.1 Dev, check the exact compatibility page for your Mac configuration before assuming FP16 headroom, because unified memory also has to leave room for the system.

Priya Krishnan

Editor, hardware & inference

Priya obsesses over the gap between box specs and what actually happens when you hit Enter in Ollama. She got here untangling friends’ builds and sticker-shock cloud bills, and she still treats every recommendation like a debt she owes the reader.

Ready to build?

Tell us what you want to run, your budget, and your use case. We'll match you to the right hardware in under a minute.

All hardware specifications, prices, and performance data referenced in this guide are sourced from OwnRig's data layer, which is based on manufacturer specifications and community benchmarks. Prices are approximate US retail as of March 2026. Performance figures may vary by configuration, driver version, and software.