Can the RTX 4090 24 GB run Wan 2.1 I2V 14B 480P?
Yes. FP8 fits on the RTX 4090 24 GB with 3.3 GB to spare.
Take FP8 (16.4 GB). In use it comes to about 20.7 GB, with 3.3 GB left over on 24 GB.
01What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Model | wan2.1_i2v_480p_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 480P file on 24 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit SAFETENSORS · Comfy-Org | 32.8 GB | 37.1 GB | 13.1 GB too big | the original weights | Hugging Face → |
| FP8 ← SAFETENSORS · Comfy-Org | 16.4 GB | 20.7 GB | fits · 3.3 GB spare | practically identical to the original | Hugging Face → |
| Q8_0 GGUF · city96 | 18.1 GB | 22.4 GB | fits · 1.6 GB spare | practically identical to the original | Hugging Face → |
| Q6_K GGUF · city96 | 14.2 GB | 18.5 GB | fits · 5.5 GB spare | very close to the original | Hugging Face → |
| Q5_K_M GGUF · city96 | 12.7 GB | 17.0 GB | fits · 7.0 GB spare | close; small differences in fine detail | Hugging Face → |
| Q4_K_M GGUF · city96 | 11.3 GB | 15.6 GB | fits · 8.4 GB spare | good; some loss in fine detail and text | Hugging Face → |
| Q3_K_M GGUF · city96 | 8.6 GB | 12.9 GB | fits · 11.1 GB spare | noticeable loss of detail | Hugging Face → |
“Needed” adds 3.5 GB of working memory for Wan 2.1 I2V 480P and a 0.8 GB reserve. Sizes 2026-10-01.
03Measured and reported results
| Label | Setup | Result | Peak VRAM | Date | Source |
|---|---|---|---|---|---|
| reported | 30 steps “100%|███| 30/30 [06:13<00:00, 12.46s/it]” Kijai WanVideoWrapper wanvideo_480p_I2V_example_01.json; 32GB system RAM, process later 'Killed' (RAM); resolution/frames not stated | 12.46 s/it | — | 2025-02-26 | github.com → |
Other people's numbers are copied as published, with a link. Send yours.
04About the RTX 4090 24 GB
The RTX 4090 24 GB is an Ada Lovelace GPU with hardware FP8, so ComfyUI can compute Comfy-Org's FP8 files natively: small and fast. (Plain FP8 files use FP8 maths with the --fast fp8_matrix_mult option.)
24 GB GDDR6X · 384-bit · 1008 GB/s · Ada Lovelace. Everything that runs on it →
05Questions
How much VRAM does Wan 2.1 I2V 480P need?
Around 12.9 GB with the smallest file (Q3_K_M) and 20.7 GB with an 8-bit file (FP8). The full 16-bit file needs about 37.1 GB.
Which Wan 2.1 I2V 480P file should I download for the RTX 4090 24 GB?
FP8 (16.4 GB) from Comfy-Org/Wan_2.1_ComfyUI_repackaged.
FP8 or Q8_0 for Wan 2.1 I2V 480P on the RTX 4090 24 GB?
FP8 (16.4 GB): the RTX 4090 24 GB computes it natively, while Q8_0 (18.1 GB) is unpacked on the fly.
How much do I need to download for Wan 2.1 I2V 480P on the RTX 4090 24 GB?
24.7 GB: wan2.1_i2v_480p_14B_fp8_e4m3fn.safetensors, umt5_xxl_fp8_e4m3fn_scaled.safetensors, wan_2.1_vae.safetensors, clip_vision_h.safetensors.