LTX Video 2.3: Cinematic Action Sequences

LTX Video 2.3 is the gold standard for high-motion consistency in AI video. This guide covers how to lock camera movement and maintain character consistency across high-speed action shots.

#Hardware Requirements

GPU	VRAM	Recommended Use
RTX 5080	16GB	Full quality, all models
RTX 4090	24GB	Full quality, batch generation
RTX 3080 16GB	16GB	Full quality, slower
RTX 3080 10GB	10GB	Reduced resolution
RTX 3060	12GB	Standard models only

Minimum: 6GB VRAM for SD1.5. FLUX requires at least 12GB.

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#Step 1 — Install Prerequisites

Python 3.10.x (required)

Download from python.org — use exactly 3.10.x, not 3.11 or 3.12.

comfyui-workflow.json

# Verify after install
python --version
# Should show: Python 3.10.x

Git

comfyui-workflow.json

git --version
# Should show: git version 2.x.x

CUDA Toolkit

Download CUDA 12.1 from nvidia.com/cuda-downloads. Match your driver version.

comfyui-workflow.json

nvcc --version
# Should show: release 12.1

#Step 2 — Clone ComfyUI

comfyui-workflow.json

cd C:\
git clone https://github.com/comfyanonymous/ComfyUI
cd ComfyUI

#Step 3 — Install Dependencies

comfyui-workflow.json

# Create virtual environment
python -m venv venv

# Activate it
.\venv\Scripts\activate

# Install PyTorch for CUDA 12.1
pip install torch torchvision torchaudio --index-url https://download.pytorch.org/whl/cu121

# Install ComfyUI requirements
pip install -r requirements.txt

#Step 4 — Install ComfyUI Manager

ComfyUI Manager lets you install custom nodes with one click.

comfyui-workflow.json

cd custom_nodes
git clone https://github.com/ltdrdata/ComfyUI-Manager
cd ..

#Step 5 — Download Your First Model

Place models in ComfyUI/models/checkpoints/

Recommended starter model:

comfyui-workflow.json

# SDXL (best quality/speed balance)
# Download from: https://huggingface.co/stabilityai/stable-diffusion-xl-base-1.0
# File: sd_xl_base_1.0.safetensors (6.5GB)

#Step 6 — Launch ComfyUI

comfyui-workflow.json

# Standard launch
python main.py

# RTX 5080 optimized (recommended)
python main.py --gpu-only --highvram

# Low VRAM mode (under 8GB)
python main.py --lowvram

Open your browser to: http://127.0.0.1:8188

#RTX 5080 Optimal Settings

These settings maximize quality and speed on 16GB VRAM:

comfyui-workflow.json

Batch size: 2–4 images
Resolution: 1024x1024 (SDXL) / 768x512 (video)
Steps: 20–30
CFG Scale: 7.0 (images) / 3.0 (video)
Sampler: dpmpp_2m
Scheduler: karras
VAE: Built-in (bake into checkpoint)
Precision: fp16

#Installing Essential Custom Nodes

In ComfyUI Manager, install these nodes first:

→ComfyUI-Impact-Pack — face detailing, segmentation
→ComfyUI_IPAdapter_plus — image prompt adapter
→ComfyUI-AnimateDiff-Evolved — video animation
→ComfyUI-VideoHelperSuite — video input/output
→rgthree-comfy — better node organization

#Your First Workflow

Once launched, load the default workflow:

→Click Load in the top menu
→Select default_workflow.json
→Change the checkpoint to your downloaded model
→Click Queue Prompt

You should see your first image generate in 15–30 seconds on an RTX 5080.

#Performance Benchmarks

Tested on RTX 5080 16GB:

Model	Resolution	Steps	Time
SDXL	1024x1024	20	~3.2s
FLUX Dev FP8	1024x1024	20	~8.1s
SD 1.5	512x512	20	~0.8s
LTX Video	768x512 97f	25	~5.4s

#Common Issues

"CUDA out of memory" — Add --lowvram to launch command, or reduce batch size to 1.

Black images — Wrong VAE. Download the correct VAE for your model.

Slow generation — Ensure --gpu-only flag is set and venv is activated.

Nodes missing — Open ComfyUI Manager and click "Install Missing Custom Nodes".

Hardware Partner

Running these workflows? ComputeAtlas.ai helps you find the right GPU

Optimization is only half the battle. Get precise VRAM benchmarks and hardware recommendations tailored for ComfyUI.

Check GPU Prices →

[AD VISUAL: GPU BENCHMARKS]