Comprehensive Guide22 min readUpdated February 2026

AI Image Generation Guide

Create stunning AI art on your own hardware

Key Takeaways
  • Flux offers best quality but needs 16GB+ VRAM
  • SDXL is the sweet spot for most users with 12GB GPUs
  • ComfyUI is the most powerful tool, worth learning
  • ControlNet and LoRAs unlock consistent, styled outputs
  • 12GB VRAM is minimum recommended, 16GB+ is ideal

Image Models Explained

Understanding the different image generation models helps you choose the right tool for your work.

Stable Diffusion 1.5

The classic. 512x512 native resolution. Runs on 6-8GB GPUs. Massive ecosystem of fine-tunes, LoRAs, and embeddings. Best for: anime, specific styles via community models.

Stable Diffusion XL (SDXL)

Major upgrade. 1024x1024 native. Needs 10-12GB VRAM. Much better composition and prompt following. Optional refiner for extra detail. Best for: general purpose high quality.

Flux

Latest from Black Forest Labs (SD creators). Best text rendering. Superior prompt understanding. Needs 16-24GB VRAM. Best for: highest quality, text in images, complex prompts.

Stable Diffusion 3

Stability AI's answer to Flux. Good text rendering. 12GB minimum. Better than SDXL, different from Flux. Best for: balanced quality/requirements.

Hardware Requirements

Image generation is VRAM-intensive. Here's what different GPUs can handle.

8GB GPUs (RTX 4060, Arc A750)

Runs SD 1.5 well. SDXL possible with optimizations (VAE tiling, fp16). Cannot run Flux. ~3-5 images per minute with SD 1.5.

12GB GPUs (RTX 3060, RTX 4070)

SDXL runs comfortably. Flux Schnell possible. ~5-8 images per minute with SDXL. Good for most users.

16GB GPUs (RTX 4070 Ti Super, 4060 Ti 16GB)

All models including Flux Dev. Comfortable batch sizes. ~8-12 images per minute. Recommended for serious work.

24GB GPUs (RTX 4090, 7900 XTX)

Maximum speed and quality. Large batches, no compromises. ~15-25 images per minute. Training LoRAs viable.

Software Options

Different interfaces serve different needs.

ComfyUI

Node-based workflow editor. Most powerful and flexible. Steeper learning curve. Preferred by professionals. Required for advanced techniques.

Automatic1111 WebUI

Traditional web interface. Easier than ComfyUI. Good extension ecosystem. Less flexible for complex workflows.

Fooocus

Simplified Midjourney-like experience. Minimal settings. Good for beginners. Limited customization.

InvokeAI

Balance of power and usability. Good for intermediate users. Canvas for inpainting.

Advanced Workflows

Unlock the full potential of local image generation.

ControlNet

Guide image generation with reference images. Pose, depth, edges, and more. Essential for consistent characters and scenes.

LoRA Fine-tunes

Small additive models that modify style or add subjects. Thousands available on CivitAI. Can train your own on 12GB+ GPUs.

Inpainting / Outpainting

Edit specific parts of images. Extend images beyond original boundaries. Essential for iterative refinement.

Upscaling

Increase resolution post-generation. Models like 4x-UltraSharp. Can go from 1024 to 4K+ with detail.

Tips & Best Practices

Improve your results with these proven techniques.

Prompt Engineering

Be specific about style, lighting, composition. Use quality boosters: 'masterpiece, best quality, highly detailed'. Negative prompts to exclude unwanted elements.

Sampling & Steps

DPM++ 2M Karras is reliable. 20-30 steps for drafts, 40-50 for finals. CFG 7-8 for balance, lower for creative freedom.

Iterative Refinement

Generate many variations quickly. Use img2img to refine favorites. Inpaint problem areas. Upscale final results.

Batch Workflow

Generate at lower resolution first. Pick best compositions. Regenerate winners at high resolution. Much faster than high-res from start.

Frequently Asked Questions

Which image model should I start with?
SDXL for most users. It balances quality and requirements. Flux if you have 16GB+ and want the best quality.
Can I match Midjourney quality locally?
Yes, especially with Flux. SDXL with good models and LoRAs also produces excellent results.
How many images can I generate per day?
Unlimited! No costs or limits. With RTX 4090, you can generate thousands per day if you wanted.
Is NVIDIA required for image generation?
No, AMD works with ROCm. NVIDIA is easier due to CUDA, but AMD 7900 XTX is popular for its 24GB VRAM.

Related Guides & Resources

Ready to Get Started?

Check our step-by-step setup guides and GPU recommendations.