Can the RTX 5080 16 GB run FLUX.1 Kontext [dev]?
Yes, but only just: FP8 leaves 1.5 GB free on the RTX 5080 16 GB.
FP8 (11.9 GB) fits with only 1.5 GB to spare (about 14.5 GB of 16 GB).
01What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Model | flux1-dev-kontext_fp8_scaled.safetensors FP8 · Comfy-Org/flux1-kontext-dev_ComfyUI | models/diffusion_models | 11.9 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 | 17.4 GB | |||
Alternatives: T5-XXL FP16 (9.8 GB). Sizes from Hugging Face, 2026-10-01.
Free ComfyUI workflow, tested on my RTX 5060 Ti: FP8 workflow (.json) · GGUF Q8_0 workflow (.json). Drag the file into ComfyUI. All workflows →
02Every FLUX.1 Kontext file on 16 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit SAFETENSORS · black-forest-labs | 23.8 GB | 26.4 GB | 10.4 GB too big | the original weights | Hugging Face → |
| FP8 ← SAFETENSORS · Comfy-Org | 11.9 GB | 14.5 GB | fits · 1.5 GB spare | practically identical to the original | Hugging Face → |
| Q8_0 GGUF · QuantStack | 12.7 GB | 15.3 GB | fits · 0.7 GB spare | practically identical to the original | Hugging Face → |
| Q6_K GGUF · QuantStack | 9.8 GB | 12.4 GB | fits · 3.6 GB spare | very close to the original | Hugging Face → |
| Q5_K_M GGUF · QuantStack | 8.4 GB | 11.0 GB | fits · 5.0 GB spare | close; small differences in fine detail | Hugging Face → |
| Q4_K_M GGUF · QuantStack | 6.9 GB | 9.5 GB | fits · 6.5 GB spare | good; some loss in fine detail and text | Hugging Face → |
| Q3_K_M GGUF · QuantStack | 5.4 GB | 8.0 GB | fits · 8.0 GB spare | noticeable loss of detail | Hugging Face → |
| Q2_K GGUF · QuantStack | 4.0 GB | 6.6 GB | fits · 9.4 GB spare | heavy loss; a last resort | Hugging Face → |
“Needed” adds 1.8 GB of working memory for FLUX.1 Kontext 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 Kontext on a RTX 5080 16 GB, send your time per image and peak VRAM and it will appear here, credited.
04About the RTX 5080 16 GB
The RTX 5080 16 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.
16 GB GDDR7 · 256-bit · 960 GB/s · Blackwell. Everything that runs on it →
05Questions
How much VRAM does FLUX.1 Kontext need?
Around 6.6 GB with the smallest file (Q2_K) and 14.5 GB with an 8-bit file (FP8). The full 16-bit file needs about 26.4 GB.
Which FLUX.1 Kontext file should I download for the RTX 5080 16 GB?
FP8 (11.9 GB) from Comfy-Org/flux1-kontext-dev_ComfyUI.
FP8 or Q8_0 for FLUX.1 Kontext on the RTX 5080 16 GB?
FP8 (11.9 GB): the RTX 5080 16 GB computes it natively, while Q8_0 (12.7 GB) is unpacked on the fly.
How much do I need to download for FLUX.1 Kontext on the RTX 5080 16 GB?
17.4 GB: flux1-dev-kontext_fp8_scaled.safetensors, t5xxl_fp8_e4m3fn.safetensors, clip_l.safetensors, ae.safetensors.