MiniMax H3 (33B) on 20 GB of VRAM
Not entirely. Even Q3_K_M is 1.4 GB over 20 GB, so ComfyUI keeps part of it in system RAM. The biggest open video release of 2026 and the most downloaded ComfyUI repo of the year: 33B parameters, 4–15 second clips with native stereo sound. Two variants (first/last-frame and reference-to-video); load one.
Nothing fits entirely, but Q3_K_M (15.6 GB) overflows by only about 1.4 GB. ComfyUI keeps that part in system RAM automatically: slower than a full fit, but usable.
Also try the INT8 file (34.0 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 · Comfy-Org | 66.3 GB | 72.1 GB | 52.1 GB too big | the original weights | Hugging Face → |
| Q8_0 GGUF · Abiray | 36.0 GB | 41.8 GB | 21.8 GB too big | practically identical to the original | Hugging Face → |
| INT8 SAFETENSORS · Comfy-Org | 34.0 GB | 39.8 GB | 19.8 GB too big | practically identical to the original | Hugging Face → |
| Q6_K GGUF · Abiray | 28.2 GB | 34.0 GB | 14.0 GB too big | very close to the original | Hugging Face → |
| Q5_K_M GGUF · Abiray | 23.9 GB | 29.7 GB | 9.7 GB too big | close; small differences in fine detail | Hugging Face → |
| Q4_K_M GGUF · Abiray | 19.9 GB | 25.7 GB | 5.7 GB too big | good; some loss in fine detail and text | Hugging Face → |
| Q3_K_M ← GGUF · Abiray | 15.6 GB | 21.4 GB | spills 1.4 GB | noticeable loss of detail | Hugging Face → |
“Needed” adds 5 GB of working memory for MiniMax H3 and a 0.8 GB reserve. Sizes 2026-10-01.
03What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Model | MiniMax-H3-FL2VA-Q3_K_M.gguf Q3_K_M · Abiray/MiniMax-H3-GGUF | models/unet | 15.6 GB | Download → |
| Text encoder | qwen3vl_32b_minimax_h3_int8_convrot.safetensors Qwen3-VL 32B INT8 (convrot) · Comfy-Org/MiniMax-H3 | models/text_encoders | 27.1 GB | Download → |
| VAE | minimax_h3_video_vae_fp16.safetensors MiniMax H3 video VAE FP16 · Comfy-Org/MiniMax-H3 | models/vae | 5.2 GB | Download → |
| Also needed | minimax_h3_audio_vae_fp32.safetensors MiniMax H3 audio VAE FP32 · Comfy-Org/MiniMax-H3 | models/vae | 0.6 GB | Download → |
| Total download · keep about the same free on disk | 48.5 GB | |||
Alternatives: Qwen3-VL 32B NVFP4 (AWQ) (15.7 GB); Qwen3-VL 32B BF16 (51.5 GB). FP4 files are listed only as alternatives unless the GPU is an RTX 50 (Blackwell). Sizes from Hugging Face, 2026-10-01.
System RAM: 64 GB or more. These files take about 48.5 GB of RAM while loaded, 54.5 GB with Windows and ComfyUI. What happens with less. calculated
04The text encoder
Take the smallest Qwen3-VL 32B file (15.7 GB): it is the only one that fits in 20 GB on its own. Sizes: 16-bit 51.5 GB, INT8 27.1 GB, NVFP4 15.7 GB. Why the encoder does not count against VRAM →