ComfyUI User Guide

A practical guide to generating images with ComfyUI on the Haiven server.

Getting Started

Access the UI

Open https://comfyui.haiven.local in your browser.

Default Workflow

ComfyUI loads with a basic text-to-image workflow. The default nodes are:

1. Load Checkpoint - Select your model
2. CLIP Text Encode (Prompt) - Positive prompt (what you want)
3. CLIP Text Encode (Prompt) - Negative prompt (what to avoid)
4. KSampler - Generation settings (steps, CFG, sampler)
5. VAE Decode - Convert latent to image
6. Save Image - Output to disk

Quick Start: Generate Your First Image

1. In Load Checkpoint, select a model (e.g., sd_xl_base_1.0.safetensors)
2. Enter your prompt in the positive CLIP Text Encode node
3. Enter negatives like blurry, low quality, watermark in the negative node
4. Click Queue Prompt (or press Ctrl+Enter)
5. Watch progress in the UI - image appears when done

Installing Models

Method 1: ComfyUI Manager (Recommended)

1. Click Manager button in the sidebar
2. Go to Install Models
3. Search for model name
4. Click Install → downloads directly to server

Method 2: Manual Upload (SCP)

From your local machine:

# Checkpoints
scp -P 25636 ~/Downloads/model.safetensors \
    elijahryoung@10.0.0.42:/mnt/models/image/checkpoints/

# LoRAs
scp -P 25636 ~/Downloads/lora.safetensors \
    elijahryoung@10.0.0.42:/mnt/models/image/loras/

After upload, click the refresh button (🔄) next to model dropdowns.

Model Directories

ComfyUI uses symlinks to access models stored in /mnt/models/image/. The following model directories are available:

Adding New Model Symlinks

If a new model type folder is needed (e.g., clip_vision):

# Create symlink as the comfyui user
sudo ln -sfn /mnt/models/image/<folder_name> /opt/comfyui/ComfyUI/models/<folder_name>

# Verify the symlink
ls -la /opt/comfyui/ComfyUI/models/<folder_name>

Available Models

Checkpoints (as of 2025-11-29)

Recommended Settings by Model

SDXL Models

• Resolution: 1024x1024 (or 896x1152, 1152x896)
• Steps: 20-30
• CFG Scale: 7-8
• Sampler: euler_ancestral or dpmpp_2m
• Scheduler: karras

SDXL Turbo

• Resolution: 512x512 or 1024x1024
• Steps: 4-8
• CFG Scale: 1-2 (very low!)
• Sampler: euler_ancestral

SD 1.5 Models

• Resolution: 512x512 (or 768x512)
• Steps: 20-30
• CFG Scale: 7-8
• Sampler: euler_ancestral or dpmpp_2m

Using LoRAs

1. Add a Load LoRA node (right-click → Add Node → loaders)
2. Connect it between Load Checkpoint and CLIP Text Encode
3. Select your LoRA file
4. Set strength_model and strength_clip (start with 0.7-1.0)
5. Include trigger words in your prompt if the LoRA requires them

Keyboard Shortcuts

Saving & Loading Workflows

Save Workflow

• Ctrl+S → saves to browser's downloads as .json
• Or: Menu → Save

Load Workflow

• Ctrl+O → select .json file
• Or: Drag .json file onto canvas
• Or: Drag image with embedded workflow onto canvas

Share Workflows

Workflow data is embedded in generated PNG images. Share the image, and others can drag it into ComfyUI to get your exact setup.

Output Images

Generated images are saved to:
- Server path: /mnt/storage/generated-images/
- Organized by date: 2025-11-29/ComfyUI_00001_.png

To download images:
1. Right-click image in UI → Save Image
2. Or browse via SCP/SFTP to /mnt/storage/generated-images/

Installing Custom Nodes

Via ComfyUI Manager

1. Click Manager → Install Custom Nodes
2. Search for the node pack
3. Click Install
4. Restart ComfyUI: sudo systemctl restart comfyui

Manual Installation

cd /opt/comfyui/ComfyUI/custom_nodes
sudo -u comfyui git clone https://github.com/user/custom-node-repo.git
sudo systemctl restart comfyui

Troubleshooting

Model not appearing

1. Verify file location: ls /mnt/models/image/checkpoints/
2. Click refresh (🔄) in the model dropdown
3. Restart: sudo systemctl restart comfyui

Generation stuck / no output

1. Check logs: journalctl -u comfyui -f
2. Look for CUDA errors or OOM (out of memory)
3. Try a smaller resolution or fewer steps

WebSocket disconnected

1. Refresh the browser page
2. If persistent, check: systemctl status comfyui

Out of VRAM

The RTX 4090 has 24GB VRAM. If you hit limits:
- Reduce resolution
- Use fewer steps
- Disable preview (saves ~1GB)
- Close other GPU applications

Check GPU usage

watch -n 1 nvidia-smi

Tips & Best Practices

1. Start simple - Get a basic workflow working before adding complexity
2. Save frequently - Use Ctrl+S to save workflow iterations
3. Use seed - Set a specific seed to reproduce results
4. Batch size 1 - Start with batch size 1, increase for variations
5. Preview method - "auto" is set; disable for faster processing
6. Negative prompts matter - Always include quality negatives

Effective Negative Prompts

blurry, low quality, watermark, signature, text, logo,
bad anatomy, bad hands, missing fingers, extra fingers,
cropped, worst quality, jpeg artifacts

Getting Help

• ComfyUI Docs: https://docs.comfy.org
• ComfyUI GitHub: https://github.com/comfyanonymous/ComfyUI
• r/comfyui: https://reddit.com/r/comfyui
• Server Logs: journalctl -u comfyui -f

Example Workflows

Basic Text-to-Image (SDXL)

Load Checkpoint (sd_xl_base_1.0)
    ↓
CLIP Text Encode (positive) → "a serene mountain lake at sunset, photorealistic"
CLIP Text Encode (negative) → "blurry, low quality, watermark"
    ↓
KSampler (steps=25, cfg=7, sampler=euler_ancestral, scheduler=karras)
    ↓
VAE Decode
    ↓
Save Image

SDXL Turbo (Fast)

Load Checkpoint (sd_xl_turbo_1.0_fp16)
    ↓
CLIP Text Encode (positive) → "your prompt"
CLIP Text Encode (negative) → ""  # can be empty for turbo
    ↓
KSampler (steps=4, cfg=1, sampler=euler_ancestral)
    ↓
VAE Decode
    ↓
Preview Image

Last updated: 2025-12-13