Can the RTX 4070 Laptop 8 GB run Stable Diffusion 1.5?
Yes. 16-bit fits on the RTX 4070 Laptop 8 GB with 4.7 GB to spare.
Take 16-bit (2.1 GB). In use it comes to about 3.3 GB, with 4.7 GB left over on 8 GB.
01What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Checkpoint | v1-5-pruned-emaonly-fp16.safetensors 16-bit · Comfy-Org/stable-diffusion-v1-5-archive | models/checkpoints | 2.1 GB | Download → |
| Total download · keep about the same free on disk | 2.1 GB | |||
One file: the checkpoint already contains the text encoders and the VAE. Sizes from Hugging Face, 2026-10-01.
02Every SD 1.5 file on 8 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit ← SAFETENSORS · Comfy-Org | 2.1 GB | 3.3 GB | fits · 4.7 GB spare | the original weights | Hugging Face → |
“Needed” adds 0.8 GB of working memory for SD 1.5 and a 0.8 GB reserve. Sizes 2026-10-01. The 2.13 GB checkpoint also holds the text encoder and VAE; the UNet alone is about 1.7 GB at 16-bit.
03The text encoder
The text encoder is inside the checkpoint, so there is nothing extra to download.
04Measured and reported results
Nobody has sent measured numbers for this pair yet. If you run SD 1.5 on a RTX 4070 Laptop 8 GB, send your time per image and peak VRAM and it will appear here, credited.
05About the RTX 4070 Laptop 8 GB
The RTX 4070 Laptop 8 GB is an Ada Lovelace GPU with hardware FP8, so ComfyUI can compute Comfy-Org's FP8 files natively: small and fast. (Plain FP8 files use FP8 maths with the --fast fp8_matrix_mult option.) As a laptop GPU it runs at a lower power limit than desktop cards (35–115 W depending on the laptop). The memory verdicts are the same; speed depends heavily on how much power the laptop maker allows.
8 GB GDDR6 · 128-bit · Ada Lovelace · 35–115 W. Everything that runs on it →
06Questions
How much VRAM does SD 1.5 need?
Around 3.3 GB with the smallest file (16-bit).
Which SD 1.5 file should I download for the RTX 4070 Laptop 8 GB?
16-bit (2.1 GB) from Comfy-Org/stable-diffusion-v1-5-archive.
How much do I need to download for SD 1.5 on the RTX 4070 Laptop 8 GB?
2.1 GB: v1-5-pruned-emaonly-fp16.safetensors.