Table of Contents
Stable Diffusion 3.5 Large is the strongest open image model in the SD lineage. 8B parameters, 16 GB FP16, generates 1024² in ~3 seconds on a 5090. Genuine alternative to FLUX.1 dev.
SD 3.5 Large fits comfortably on RTX 5080 16 GB or larger. ComfyUI workflow runs out of the box. Stability Community License — free for <$1M annual revenue, paid above. Strong alternative to FLUX.1 dev for commercial deployments.
SD 3.5 variants
- SD 3.5 Large: 8B params, ~16 GB FP16, the production target
- SD 3.5 Medium: 2.5B params, ~6 GB FP16, fast iteration
- SD 3.5 Large Turbo: 4-step distilled, ~16 GB FP16
Hardware sizing
| GPU | SD 3.5 Large FP16 | SD 3.5 Medium | Notes |
|---|---|---|---|
| RTX 5060 Ti 16 GB | Tight (just fits) | Comfortable | Single image at a time |
| RTX 5080 16 GB | Comfortable | Comfortable | Sweet spot |
| RTX 5090 32 GB | Plenty | Plenty | Multi-pipeline |
| RTX 6000 Pro | Plenty | Plenty | Multi-model |
Setup
huggingface-cli login # SD 3.5 is gated
huggingface-cli download stabilityai/stable-diffusion-3.5-large \
--local-dir ~/ComfyUI/models/checkpoints/sd35-large
# Run ComfyUI
cd ~/ComfyUI && python main.py --listen 0.0.0.0 --port 8188Licensing
Stability Community License: free for organisations with <$1M annual revenue or <1M monthly active users. Above that, requires a Stability commercial license.
Compared to FLUX.1 dev (non-commercial only) and FLUX.1 schnell (Apache 2.0), SD 3.5 Large sits between — broadly commercial-friendly with a clear paid path at scale.
Verdict
For commercial image-gen products under the $1M revenue threshold, SD 3.5 Large is the right pick. Above that threshold, FLUX.1 schnell (Apache 2.0) is cheaper. For pure quality, FLUX.1 dev still slightly leads but with restrictive licensing.
Bottom line
SD 3.5 Large for commercial deployments under $1M revenue. FLUX.1 schnell or paid Stability license above that. See FLUX vs SD 3.5 comparison.
