Can the RTX 5070 12 GB run FLUX.1 Fill [dev]?
Not at full quality. The 16-bit and 8-bit files are too big for the RTX 5070 12 GB; the largest that fits is Q5_K_S (8.3 GB).
Q5_K_S (8.3 GB) fits with only 1.1 GB to spare (about 10.9 GB of 12 GB). Quality: close; small differences in fine detail. For better quality, Q6_K (9.9 GB) also runs, with about 0.5 GB spilling into system RAM - a little slower, still practical.
01What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Model | flux1-fill-dev-Q5_K_S.gguf Q5_K_S · YarvixPA/FLUX.1-Fill-dev-GGUF | models/unet | 8.3 GB | Download → |
| Text encoder | t5xxl_fp8_e4m3fn.safetensors T5-XXL FP8 · comfyanonymous/flux_text_encoders | models/text_encoders | 4.9 GB | Download → |
| Text encoder | clip_l.safetensors CLIP-L · comfyanonymous/flux_text_encoders | models/text_encoders | 0.2 GB | Download → |
| VAE | ae.safetensors FLUX.1 VAE (ae) · Comfy-Org/Lumina_Image_2.0_Repackaged | models/vae | 0.3 GB | Download → |
| Total download · keep about the same free on disk | 13.8 GB | |||
Alternatives: T5-XXL FP16 (9.8 GB). Sizes from Hugging Face, 2026-10-01.
02Every FLUX.1 Fill file on 12 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit SAFETENSORS · black-forest-labs | 23.8 GB | 26.4 GB | 14.4 GB too big | the original weights | Hugging Face → |
| Q8_0 GGUF · YarvixPA | 12.7 GB | 15.3 GB | 3.3 GB too big | practically identical to the original | Hugging Face → |
| Q6_K GGUF · YarvixPA | 9.9 GB | 12.5 GB | spills 0.5 GB | very close to the original | Hugging Face → |
| Q5_K_S ← GGUF · YarvixPA | 8.3 GB | 10.9 GB | fits · 1.1 GB spare | close; small differences in fine detail | Hugging Face → |
| Q4_K_S GGUF · YarvixPA | 6.8 GB | 9.4 GB | fits · 2.6 GB spare | good; some loss in fine detail and text | Hugging Face → |
| Q3_K_S GGUF · YarvixPA | 5.2 GB | 7.8 GB | fits · 4.2 GB spare | noticeable loss of detail | Hugging Face → |
“Needed” adds 1.8 GB of working memory for FLUX.1 Fill and a 0.8 GB reserve. Sizes 2026-10-01.
03Measured and reported results
Nobody has sent measured numbers for this pair yet. If you run FLUX.1 Fill on a RTX 5070 12 GB, send your time per image and peak VRAM and it will appear here, credited.
04With more VRAM
With 16 GB you could run FLUX.1 Fill at 8-bit or better (Q8_0, 12.7 GB) with no offloading: for example on the RTX 5080 16 GB, RTX 5070 Ti 16 GB, RTX 5060 Ti 16 GB.
What changes from the RTX 5070 12 GB to the RTX 5070 Ti 16 GB →
05About the RTX 5070 12 GB
The RTX 5070 12 GB is a Blackwell GPU with FP8 and FP4 hardware: ComfyUI computes Comfy-Org's FP8 files natively here, and NVFP4 files (where a model offers them) are faster still.
12 GB GDDR7 · 192-bit · 672 GB/s · Blackwell. Everything that runs on it →
06Questions
How much VRAM does FLUX.1 Fill need?
Around 7.8 GB with the smallest file (Q3_K_S) and 15.3 GB with an 8-bit file (Q8_0). The full 16-bit file needs about 26.4 GB.
Which FLUX.1 Fill file should I download for the RTX 5070 12 GB?
Q5_K_S (8.3 GB) from YarvixPA/FLUX.1-Fill-dev-GGUF. Load it with Unet Loader (GGUF) from the ComfyUI-GGUF node pack.
How much do I need to download for FLUX.1 Fill on the RTX 5070 12 GB?
13.8 GB: flux1-fill-dev-Q5_K_S.gguf, t5xxl_fp8_e4m3fn.safetensors, clip_l.safetensors, ae.safetensors.