FLUX.2 [dev] on 20 GB of VRAM
Not at full quality. The 16-bit and 8-bit files are too big for 20 GB; the largest that fits is Q3_K_M (16.0 GB). The 32B second-generation FLUX. Very capable and very heavy: even 4-bit files are around 20 GB, and the text encoder is a 24B language model.
Q3_K_M (16.0 GB) fits with only 0.7 GB to spare (about 19.3 GB of 20 GB). Quality: noticeable loss of detail.
Also try the FP8 file (35.5 GB) on NVIDIA GPUs. It does not fit entirely, but a current ComfyUI streams the overflow from RAM and native 8-bit files often beat a small GGUF that does fit. Dynamic VRAM →
01Other amounts of VRAM
02Every file, on 20 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit SAFETENSORS · black-forest-labs | 64.4 GB | 67.7 GB | 47.7 GB too big | the original weights | Hugging Face → |
| Q8_0 GGUF · city96 | 35.0 GB | 38.3 GB | 18.3 GB too big | practically identical to the original | Hugging Face → |
| FP8 SAFETENSORS · Comfy-Org | 35.5 GB | 38.8 GB | 18.8 GB too big | practically identical to the original | Hugging Face → |
| Q6_K GGUF · city96 | 27.4 GB | 30.7 GB | 10.7 GB too big | very close to the original | Hugging Face → |
| Q5_K_M GGUF · city96 | 24.1 GB | 27.4 GB | 7.4 GB too big | close; small differences in fine detail | Hugging Face → |
| Q4_K_M GGUF · city96 | 20.1 GB | 23.4 GB | 3.4 GB too big | good; some loss in fine detail and text | Hugging Face → |
| Q3_K_M ← GGUF · city96 | 16.0 GB | 19.3 GB | fits · 0.7 GB spare | noticeable loss of detail | Hugging Face → |
| Q2_K GGUF · city96 | 12.9 GB | 16.2 GB | fits · 3.8 GB spare | heavy loss; a last resort | Hugging Face → |
“Needed” adds 2.5 GB of working memory for FLUX.2 dev and a 0.8 GB reserve. Sizes 2026-10-01.
03What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Model | flux2-dev-Q3_K_M.gguf Q3_K_M · city96/FLUX.2-dev-gguf | models/unet | 16.0 GB | Download → |
| Text encoder | mistral_3_small_flux2_fp8.safetensors Mistral 3 Small FP8 · Comfy-Org/flux2-dev | models/text_encoders | 18.0 GB | Download → |
| VAE | flux2-vae.safetensors FLUX.2 VAE · Comfy-Org/flux2-dev | models/vae | 0.3 GB | Download → |
| Total download · keep about the same free on disk | 34.3 GB | |||
Alternatives: Mistral 3 Small BF16 (35.6 GB). Sizes from Hugging Face, 2026-10-01.
System RAM: 48 GB or more. These files take about 34.3 GB of RAM while loaded, 40.3 GB with Windows and ComfyUI. What happens with less. calculated