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MiniMax H3 BF16: Compatible GPUs, VRAM and Download
| Item | Value |
|---|---|
| File name | minimax_h3_fl2va_bf16.safetensors |
| Component | Main model (diffusion) |
| Quant / format | BF16 |
| Size | 66.28 GB |
| ComfyUI folder | diffusion_models (main model folder) |
| Source | Comfy-Org/MiniMax-H3 |
Which GPUs can run it
736 × 416 · 5s: 1 GPUs workable
1344 × 768 · 5s: 1 GPUs workable
1344 × 768 · 15s: pick a smaller alternative
None — switch to a smaller quant or lower tier
“Workable” = estimated status ok or warn with 32GB RAM / fast-disk (warn means weight offloading and noticeably slower).
Every quant in this family, side by side
Same family = different quants of the same base variant. They are interchangeable — what changes is size, speed and quality loss. "Peak" is a rough VRAM estimate (file size × 0.6, floor 8G).
| File | Quant | Size | Pruned | VRAM fit |
|---|---|---|---|---|
| P- W4A8 | W4A8 | 12.54 GB (peak ~8G) | pruned | for 12-16GB cards |
| P- FP8 | FP8 Scaled | 20.96 GB (peak ~13G) | pruned | wants 24GB+ |
| P- INT8 | INT8 ConvRot | 20.97 GB (peak ~13G) | pruned | wants 24GB+ |
| INT8 | INT8 ConvRot | 34.04 GB (peak ~20G) | full | wants 24GB+ |
| P- BF16 | BF16 | 40.23 GB (peak ~24G) | pruned | wants 24GB+ |
| BF16 ← this page | BF16 | 66.28 GB (peak ~40G) | full | wants 24GB+ |
Rule of thumb: anything under 10GB fits an 8GB card, the 10-16GB tier targets 12-16GB cards, and files above 16GB want 24GB+. Within this family the flagged P- INT8 is the official default — take it unless you have a reason not to. The smallest here is P- W4A8 (12.54GB) and the largest is BF16 (66.28GB); this file (66.28GB) sits in the "wants 24GB+" tier. About this quant: the full-precision baseline: highest quality ceiling, biggest files — mostly for large-VRAM, max-quality setups.
Who is this file for?
Role in the pipeline: the main model — it sets generation quality and speed and is the biggest download; swapping quants changes detail and pace, not how you write prompts.Frankly, a 66.28GB file is all but guaranteed to run through weight offloading unless you have 40GB+ of VRAM. Most people should grab a 10-25GB pruned INT8 or W4A8 build from the table above instead (this family's P- INT8 at 20.97GB and P- W4A8 at 12.54GB are a fraction of the size); this one is for "VRAM to spare, full precision only" setups. Full-precision weights also read from disk more slowly, so expect a longer first load.
Fastest vs. minimum hardware
"Fastest" = the card with the shortest estimated time; "floor" = the smallest-VRAM card that still runs it. Times include model load and text encoding; the first run also compiles kernels.
- 736 × 416 · 5s: fastest RTX 4090 48GB (modded) at ~1 min 47 s (1/49 GPUs workable) · floor RTX 4090 48GB (modded) (needs weight offloading — noticeably slower)
- 1344 × 768 · 5s: fastest RTX 4090 48GB (modded) at ~4 min 49 s (1/49 GPUs workable) · floor RTX 4090 48GB (modded) (needs weight offloading — noticeably slower)
- 1344 × 768 · 15s: no workable GPU at all — step down a quant first.
Download, place, refresh — 3 steps
- Grab it: the button above redirects to the official HuggingFace / GitHub repo — /go is just a redirect, we never rehost. Skip cloud-drive mirrors; if HuggingFace is slow or blocked on your network, a mirror can speed up the transfer, but verify the file against the official repo. Keep at least 2× the file size free on disk.
- Place it: drop the file into diffusion_models (main model folder) exactly as shown in the spec table, filename untouched — loaders locate files by folder and name, so a rename makes it "vanish".
- Load it: hit Refresh in ComfyUI (it only scans folders at startup or on refresh), then pick the file in the loader node. loader node: Load Diffusion Model (GGUF files go through the ComfyUI-GGUF Unet Loader).
Sanity check: once downloaded, compare the size on disk with the 66.28GB listed here. Way off? The download is incomplete — browsers sometimes keep a half-written file looking like a finished one — so delete it and pull again.
Also required: It takes all three to render: besides this file you need the text encoder NVFP4 AWQ and the VAEs BF16 + BF16 — miss any one of them and the workflow errors out on the spot.
Won't load? Check these three
- Nothing shows up after Refresh: nine times out of ten it's the wrong folder — re-check the ComfyUI folder row in the spec table above. The file must sit inside ComfyUI's models/ subfolder, and no, a desktop shortcut doesn't count.
- Instant OOM the moment it loads: make sure no other big model is sitting in VRAM first, then step down to a smaller quant from the table above — the INT8 vs BF16 guide has the full math on why brute-forcing backfires.
- Renamed it and now nothing picks it up: loaders match by filename (GGUF metadata stores the original name too), so restore the original name and hit Refresh once more.
→ Run the numbers for your RAM/budget in the calculator (this file pre-filled)
FAQ
How much VRAM does minimax_h3_fl2va_bf16.safetensors need?
The file is 66.28GB (Main model (diffusion)). Runtime VRAM also depends on resolution and duration; a 720p-class short clip typically needs roughly 40GB+ of free VRAM. Run the calculator for your exact card.
Where does this file go in ComfyUI?
diffusion_models (main model folder). Keep the filename as-is; refresh ComfyUI and select it in the matching loader.
How does it compare with other quantizations?
See sibling entries in the model library and the INT8/BF16 comparison article. Rule of thumb: 8GB → GGUF Q3/Q2; 12-16GB → pruned INT8 or W4A8; 24GB+ → full INT8 or NVFP4 (RTX 50).
Similar files: INT8 · P- BF16 · P- INT8 · P- FP8 · BF16 · INT8 · P- BF16 · P- INT8 · P- FP8 · P- W4A8
Related: Model library · INT8/BF16 comparison · 8GB VRAM setups