HunyuanVideo (13B, original) on 6 GB of VRAM
Not entirely. Even Q4_K_M is 6.2 GB over 6 GB, so ComfyUI keeps part of it in system RAM. The original 13B HunyuanVideo from December 2024. Largely replaced by the lighter HunyuanVideo 1.5, but still widely used with its LoRAs.
The smallest sensible file, Q4_K_M (7.9 GB), needs about 12.2 GB - 6.2 GB more than 6 GB GPU has. ComfyUI can still run it by streaming part of the model from system RAM. How much slower that is depends on your ComfyUI version, the file format and the PCIe link - see the note below.
Also try the FP8 file (13.2 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 6 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit SAFETENSORS · Comfy-Org | 25.6 GB | 29.9 GB | 23.9 GB too big | the original weights | Hugging Face → |
| Q8_0 GGUF · city96 | 14.0 GB | 18.3 GB | 12.3 GB too big | practically identical to the original | Hugging Face → |
| FP8 SAFETENSORS · Kijai | 13.2 GB | 17.5 GB | 11.5 GB too big | practically identical to the original | Hugging Face → |
| Q6_K GGUF · city96 | 11.0 GB | 15.3 GB | 9.3 GB too big | very close to the original | Hugging Face → |
| Q5_K_M GGUF · city96 | 9.4 GB | 13.7 GB | 7.7 GB too big | close; small differences in fine detail | Hugging Face → |
| Q4_K_M ← GGUF · city96 | 7.9 GB | 12.2 GB | 6.2 GB too big | good; some loss in fine detail and text | Hugging Face → |
| Q3_K_M GGUF · city96 | 6.2 GB | 10.5 GB | 4.5 GB too big | noticeable loss of detail | Hugging Face → |
“Needed” adds 3.5 GB of working memory for HunyuanVideo 13B and a 0.8 GB reserve. Sizes 2026-10-01.
03What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Model | hunyuan-video-t2v-720p-Q4_K_M.gguf Q4_K_M · city96/HunyuanVideo-gguf | models/unet | 7.9 GB | Download → |
| Text encoder | llava_llama3_fp8_scaled.safetensors LLaVA-Llama3 FP8 (scaled) · Comfy-Org/HunyuanVideo_repackaged | models/text_encoders | 9.1 GB | Download → |
| Text encoder | clip_l.safetensors CLIP-L · Comfy-Org/HunyuanVideo_repackaged | models/text_encoders | 0.2 GB | Download → |
| VAE | hunyuan_video_vae_bf16.safetensors HunyuanVideo VAE BF16 · Comfy-Org/HunyuanVideo_repackaged | models/vae | 0.5 GB | Download → |
| Total download · keep about the same free on disk | 17.7 GB | |||
Alternatives: LLaVA-Llama3 FP16 (16.1 GB). Only for some workflows: LLaVA-Llama3 vision (0.6 GB, I2V only). Sizes from Hugging Face, 2026-10-01.
04The text encoder
At 9.1 GB even the smallest LLaVA-LLaMA-3 8B + CLIP-L file is too big for 6 GB, so it runs from system RAM. That slows down reading the prompt, not the picture. Sizes: 16-bit 16.1 GB, FP8 9.1 GB (plus CLIP-L (0.25 GB)). Why the encoder does not count against VRAM →