This article was originally published on runaihome.com
Three generations of image models now live in a typical ComfyUI installation (Windows users: see our ComfyUI Windows setup guide), and the choice between them isn't obvious. SD 1.5 still commands the deepest fine-tune ecosystem ever built around a single model. SDXL is the default backbone for most home-lab artists. Flux.1 produces images that read as professional photography — handles human hands, readable in-image text, and complex lighting in ways that SD and SDXL can't reliably match.
The tradeoff is hardware. Flux requires 12–24 GB VRAM and takes 4–10× longer per image than SDXL on the same GPU. Whether that matters depends on how many images you generate per session and what GPU you're running. This article quantifies those costs: verified generation times across two GPU tiers, converted into dollar-per-image electricity costs at the current US average of $0.182/kWh (EIA 2026 forecast), and a cloud comparison that tells you when a $30/month Midjourney subscription is still the smarter call.
The Three Models at a Glance
Model
