Can the Arc B580 12 GB run Stable Diffusion 1.5?
Download 16-bit (2.1 GB). With the model's working memory it needs about 3.3 GB, leaving 8.7 GB spare on 12 GB. Quality: the original weights.
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 read from Hugging Face (2026-09-25). “Download” links start the file directly; the file name links are the same files the official ComfyUI workflows use.
System RAM: 16 GB or more. ComfyUI keeps the model file, the text encoder and the VAE in system RAM and moves them to the GPU as needed. With this set of files that is about 2.1 GB, plus roughly 6 GB for Windows, ComfyUI and a browser: 8.1 GB in total. With less RAM it still runs, but Windows starts swapping to disk and loading gets very slow. calculated
02Every SD 1.5 file on 12 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit ← SAFETENSORS · Comfy-Org | 2.1 GB | 3.3 GB | fits · 8.7 GB spare | the original weights | Hugging Face → |
Sizes from the Hugging Face file listing, read 2026-09-25. “Needed” = file + 0.8 GB working memory for this model + 0.8 GB kept free for the system. 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.
04About this GPU
Intel Arc GPUs run ComfyUI through PyTorch's native XPU support on Windows 11 and Linux. Memory works the same as on NVIDIA, so the fit verdicts apply. FP8 files save memory but give no speed-up, and some custom nodes are NVIDIA-only.
Arc B580 12 GB: 12 GB GDDR6 · 192-bit · 456 GB/s · Battlemage. Everything that runs on the Arc B580 12 GB →
05What more VRAM would change
Nothing to gain for this model: the Arc B580 12 GB already runs a top-quality file entirely in VRAM. More memory would only help with bigger images, longer clips or several models at once.
What changes from the Arc B580 12 GB to the RTX 5060 Ti 16 GB →
06Measured and reported results
Nobody has sent measured numbers for this pair yet. If you run SD 1.5 on a Arc B580 12 GB, send your time per image and peak VRAM and it will appear here, credited.
07Questions
How much VRAM does SD 1.5 need?
Around 3.3 GB with the smallest file (16-bit), counting working memory and a small system reserve.
Which SD 1.5 file should I download for the Arc B580 12 GB?
16-bit (2.1 GB) from Comfy-Org/stable-diffusion-v1-5-archive.
Is FP8 faster than GGUF on the Arc B580 12 GB?
No. This GPU has no FP8 compute, so ComfyUI converts FP8 weights back before the maths. FP8 only saves memory here; Q8_0 GGUF is the closer-to-original 8-bit pick.
How much do I need to download for SD 1.5 on the Arc B580 12 GB?
About 2.1 GB for the model file, text encoder and VAE listed on this page, and the same again free on disk. With a 12 GB card, 16 GB of system RAM or more is recommended.