SD 1.5: 4K Tile Upscale Pipeline in ComfyUI
Blueprint for turning a 1024px render into a sharp 4096px master with SD 1.5 (4 GB–6 GB VRAM) using Load Upscale Model (4x-UltraSharp) → Ultimate SD Upscale (denoise 0.28).
Updated Oct 17, 2026 · 1 min read
- Model Architecture
- SD 1.5
- Workflow Task
- 4K Tile Upscale Pipeline
- VRAM Requirement
- 4 GB–6 GB
- Primary Loader
- Load Checkpoint
- Model Directory
- models/checkpoints/
Node graph blueprint: SD 1.5 × 4K Tile Upscale Pipeline
This route pairs **SD 1.5** with a **4K Tile Upscale Pipeline** setup designed for turning a 1024px render into a sharp 4096px master. Place your model weights in `models/checkpoints/` and start the graph with **Load Checkpoint**.
Core wiring chain: `Load Upscale Model (4x-UltraSharp) → Ultimate SD Upscale (denoise 0.28)`. Connect your positive and negative conditioning from CLIP Text Encode into KSampler and decode to RGB pixels.
VRAM tuning and execution tips on Windows
- **Memory target (4 GB–6 GB):** If your GPU sits at 8 GB or 12 GB, use FP8 or GGUF Q4/Q5 weights and swap in VAE Decode (Tiled) to avoid end-of-pass memory spikes.
- **Workflow persistence:** Every image saved by this route embeds the full JSON graph inside the PNG metadata — drag the output back onto ComfyUI Studio anytime to resume.
- **Get the app:** Download the Windows desktop or portable build from /download.
FAQs
Which loader node do I use for SD 1.5 in a 4K Tile Upscale Pipeline?
Use `Load Checkpoint` with weights stored in `models/checkpoints/`, then wire the output into `Load Upscale Model (4x-UltraSharp) → Ultimate SD Upscale (denoise 0.28)`.
How much VRAM does SD 1.5 need for 4K Tile Upscale Pipeline?
Target VRAM is 4 GB–6 GB. On 8 GB cards, load quantized FP8 or GGUF weights and enable tiled VAE decoding.
Run on your hardware. Free forever.
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