Can the RTX 3090 24 GB run Wan 2.1 I2V 14B 720P?
Yes, but only just: FP8 leaves 0.8 GB free on the RTX 3090 24 GB.
FP8 (16.4 GB) fits with only 0.8 GB to spare (about 23.2 GB of 24 GB).
01What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Model | wan2.1_i2v_720p_14B_fp8_e4m3fn.safetensors FP8 · Comfy-Org/Wan_2.1_ComfyUI_repackaged | models/diffusion_models | 16.4 GB | Download → |
| Text encoder | umt5_xxl_fp8_e4m3fn_scaled.safetensors UMT5-XXL FP8 (scaled) · Comfy-Org/Wan_2.1_ComfyUI_repackaged | models/text_encoders | 6.7 GB | Download → |
| VAE | wan_2.1_vae.safetensors Wan 2.1 VAE · Comfy-Org/Wan_2.1_ComfyUI_repackaged | models/vae | 0.3 GB | Download → |
| Also needed | clip_vision_h.safetensors CLIP Vision H · Comfy-Org/Wan_2.1_ComfyUI_repackaged | models/clip_vision | 1.3 GB | Download → |
| Total download · keep about the same free on disk | 24.7 GB | |||
Alternatives: UMT5-XXL FP16 (11.4 GB). Sizes from Hugging Face, 2026-10-01.
02Every Wan 2.1 I2V 720P file on 24 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit SAFETENSORS · Comfy-Org | 32.8 GB | 39.6 GB | 15.6 GB too big | the original weights | Hugging Face → |
| Q8_0 GGUF · city96 | 18.1 GB | 24.9 GB | spills 0.9 GB | practically identical to the original | Hugging Face → |
| FP8 ← SAFETENSORS · Comfy-Org | 16.4 GB | 23.2 GB | fits · 0.8 GB spare | practically identical to the original | Hugging Face → |
| Q6_K GGUF · city96 | 14.2 GB | 21.0 GB | fits · 3.0 GB spare | very close to the original | Hugging Face → |
| Q5_K_M GGUF · city96 | 12.7 GB | 19.5 GB | fits · 4.5 GB spare | close; small differences in fine detail | Hugging Face → |
| Q4_K_M GGUF · city96 | 11.3 GB | 18.1 GB | fits · 5.9 GB spare | good; some loss in fine detail and text | Hugging Face → |
| Q3_K_M GGUF · city96 | 8.6 GB | 15.4 GB | fits · 8.6 GB spare | noticeable loss of detail | Hugging Face → |
“Needed” adds 6 GB of working memory for Wan 2.1 I2V 720P 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 Wan 2.1 I2V 720P on a RTX 3090 24 GB, send your time per image and peak VRAM and it will appear here, credited.
04About the RTX 3090 24 GB
The RTX 3090 24 GB (Ampere) has no FP8 compute. FP8 files still load and save memory, but ComfyUI converts them back before the maths, so there is no speed gain - Q8_0 GGUF is the closer-to-original 8-bit choice. ComfyUI can compute INT8 files natively on NVIDIA, which is worth a try where a model offers one.
24 GB GDDR6X · 384-bit · 936 GB/s · Ampere. Everything that runs on it →
05Questions
How much VRAM does Wan 2.1 I2V 720P need?
Around 15.4 GB with the smallest file (Q3_K_M) and 23.2 GB with an 8-bit file (FP8). The full 16-bit file needs about 39.6 GB.
Which Wan 2.1 I2V 720P file should I download for the RTX 3090 24 GB?
FP8 (16.4 GB) from Comfy-Org/Wan_2.1_ComfyUI_repackaged.
FP8 or Q8_0 for Wan 2.1 I2V 720P on the RTX 3090 24 GB?
Q8_0 (18.1 GB). The RTX 3090 24 GB has no FP8 maths, so FP8 (16.4 GB) only saves memory and is a step further from the original.
How much do I need to download for Wan 2.1 I2V 720P on the RTX 3090 24 GB?
24.7 GB: wan2.1_i2v_720p_14B_fp8_e4m3fn.safetensors, umt5_xxl_fp8_e4m3fn_scaled.safetensors, wan_2.1_vae.safetensors, clip_vision_h.safetensors.