GPUs/AMD Radeon RX 7900 XT/Stable Diffusion 3.5 Large

Can AMD Radeon RX 7900 XT run Stable Diffusion 3.5 Large?

8B parameter Image Gen model on 20GB GDDR6

Yes — runs at full precision
~2.6-3.5 img/min
SpeedFastest possible inference
QualityMaximum quality, no degradation
Stable Diffusion 3.5 Large works best with NVIDIA CUDA. Your AMD GPU may have limited or no support.

VRAM Requirements

Stable Diffusion 3.5 Large is a 8B parameter model. At full precision (FP16), it requires 18GB of VRAM. Your AMD Radeon RX 7900 XT has 20GB — enough to run it without any quantization.

FP16 (Full Precision)18GB (2GB free)

Maximum quality, no quantization

Q8 (8-bit)10GB (10GB free)

Near-lossless, ~50% size reduction

Q4 (4-bit)7GB (13GB free)

Good quality, ~75% size reduction

Your GPU VRAM: 20GB GDDR6 at 800 GB/s bandwidth
Recommended system RAM: 40GB DDR5 (2x GPU VRAM minimum for model overflow)

What This Means in Practice

AMD Radeon RX 7900 XT runs Stable Diffusion 3.5 Large at full precision with room to spare. You can generate high-resolution images, use complex prompts, and batch multiple generations. Expect fast generation times at 1024x1024 and above.

How to Set It Up

Step 1: Install ComfyUI

git clone https://github.com/comfyanonymous/ComfyUI.git && cd ComfyUI && pip install -r requirements.txt

ComfyUI is the recommended UI for Stable Diffusion and FLUX models.

Step 2: Download the model

Download Stable Diffusion 3.5 Large weights from HuggingFace and place them in ComfyUI/models/. The model is approximately 18GB at full precision.

Step 3: Launch and generate

python main.py

Open http://localhost:8188 in your browser. You can use the full precision weights.

AMD Radeon RX 7900 XT Specs

VRAM20GB GDDR6
Memory Bandwidth800 GB/s
TDP315W
CUDA CoresN/A
Street Price~$700
AI Rating4/10

Other Image Gen Models on AMD Radeon RX 7900 XT

About Stable Diffusion 3.5 Large

Latest SD architecture. Better quality than SDXL, slightly more VRAM hungry.

Category: Image Gen · Parameters: 8B · CUDA required: Recommended