MiniMax-H3 Turbo — one file, no Python

MiniMax-H3 renders video and synchronized stereo audio from one prompt, in one transformer, on two flow schedules. larryvrh's Turbo LoRA brings it to four sampling steps. This is both of them in the CMF container — the DiT, the Qwen3-VL prompt encoder, the video VAE decoder and the audio vocoder in a single memory-mapped file — running on cortiq, a Rust binary with no ML framework underneath.

The reference checkout is 124.4 GB across four files plus a ComfyUI install. Here it is one file between 13.2 and 23.9 GB, and which one you take is decided by your VRAM.

Same prompt, three files

"A corgi in a chef hat flipping a pancake, sizzling sounds and a cheerful bark." — 512×288, 39 frames, seed 42, four steps, nothing but the prompt.

The 13.2 GB file is the one to take if you have 16–20 GB of VRAM: it holds the whole run resident instead of paging, and it is still four bits everywhere. Two bits is published as a dead end, not a choice — why, with numbers.

The GIFs are silent and the audio is half the model, so take an mp4. One transformer denoises picture and sound together in one packed sequence.

Which file

Text-to-video everywhere; the fl2va files also take a first and/or last frame (--first-frame/--last-frame, binary P6 PPM). The compact clipproj4b-fl2va file was verified frame-for-frame: the conditioning image comes back as frame 0 of the render. One honest caveat: its ClipProj projection was fitted on text-only encoder activations, so with a picture in the prompt the conditioning quality on complex scenes is still being compared against the full-encoder fl2va files — report what you see in the discussions. (keyframes). The release's third path, ref2va, is not ported. The Turbo LoRA is merged into the weights, so the file IS the 4-step model — nothing else to download. 47.83 B parameters, 2 361 tensors, cortiq verify clean.

Keyframe to video

cortiq animate mmh3-turbo-fl2va-q4tp.cmf \
  --prompt "the corgi lifts the pan and flips the pancake high, sizzling" \
  --first-frame keyframe.ppm --out flip.avi

One picture conditions the run twice, and both halves matter. Its VAE latent becomes a row the DiT holds at a timestep of its own near 1 — a condition, not noise being removed — and never denoises. The picture ITSELF goes to the prompt encoder through Qwen3-VL's vision tower, as "<Picture 1>: " and a vision block: at 512×288 that is 144 tokens of the 168 the prompt above carries. Leave one out and the model is conditioned on something the reference never conditions on.

--last-frame anchors the other end. The first frame is a geometry anchor and is stretched to the canvas; the last one follows and is cover-cropped, which is what the reference does with each. Frames come in as binary P6 PPM.

Running it

1. Get the runtime

cortiq is one Rust binary. Either install it —

cargo install cortiq-cli          # needs Rust 1.85+; brings the GPU backend

— or take a prebuilt archive from the latest release (Linux x86-64, macOS on Apple Silicon and Intel, Windows x86-64 and ARM64; each ships a .sha256). Nothing else is required: no Python, no PyTorch, no CUDA toolkit, no ffmpeg.

Check it took:

cortiq --version

2. Get the weights

One file. Pick it from Which file above — this is the text-to-video default; swap the name for mmh3-turbo-clipproj4b-q4tp.cmf if you are on a 20 GB card.

pip install -U "huggingface_hub[cli]"      # only to fetch the file
hf download infosave/MiniMax-H3-Turbo-cmf mmh3-turbo-q4tp.cmf --local-dir .

Confirm it arrived whole — the container carries a hash per tensor:

cortiq verify mmh3-turbo-q4tp.cmf     # → ✓ all tensor hashes match
cortiq info   mmh3-turbo-q4tp.cmf     # → arch, layers, 47.83B params

3. Render

cortiq animate mmh3-turbo-q4tp.cmf \
  --prompt "A corgi in a chef hat flipping a pancake, sizzling sounds and a cheerful bark." \
  --width 512 --height 288 --frames 39 --steps 4 --seed 42 \
  --out corgi.avi

That writes corgi.avi — MJPEG video with PCM stereo, playable in VLC, mpv, QuickTime and Windows Media Player — and corgi.wav beside it. The JPEG encoder and the RIFF muxer are inside the binary: a pipeline that ends in a shell-out to a 20 MB dependency is not a pipeline you can ship. If you want an mp4 for a browser, remux it yourself; the model never needs one.

On a GPU. Nothing to opt into any more: cortiq probes this file's own first qkv weight against the host on startup and takes the device arm only if they agree, so the arm that renders is the arm that was checked.

cortiq animate mmh3-turbo-q4tp.cmf --prompt "…" --out corgi.avi

On one RTX 5090, 512×288, 39 frames: 60.2 s at the default four steps (91.6 s at eight, 42.8 at two). RUST_LOG=info prints a per-stage breakdown for every run, and the full table is under What it costs to run below. The whole pipeline stays on the card — the DiT block, both VAE decoders, and the vocoder's dilated convolutions — so nothing but the finished frames crosses the bus. CMF_MMH3_GPU=0 forces the host path if you want to compare.

Two cards. A render does not split across them, and should not: the DiT block and both decoders are already resident, so a second card would only add a bus crossing to a pipeline that no longer has one. Two cards double your clips, not your clip — run two processes, one pinned to each:

CMF_GPU_ADAPTER=0 cortiq animate model.cmf --prompt "…" --seed 1 --out a.avi &
CMF_GPU_ADAPTER=1 cortiq animate model.cmf --prompt "…" --seed 2 --out b.avi &
wait

cortiq gpu lists the cards and their indices. For text models the same binary both splits and replicates across cards — see docs/MULTI_GPU.md.

Options that matter

What it needs

RAM at least the file's size — 24 GB — or every step faults on non-resident pages; the weights are memory-mapped, not read. Disk: 24 GB. A GPU is optional and wants ~14 GB of VRAM for the DiT's planes. No network access at run time.

mmh3-turbo-clipproj4b-q4tp.cmf asks for 14 GB of RAM and disk instead, and peaks at 15.1 GB of VRAM — a whole-run maximum, polled, not a snapshot. That is what makes it the one to reach for on a 20 GB card: below that the prompt encoder pages, and on this workload paging costs more than any kernel.

Field notes: 24 GB Macs and 20 GB cards

Two users measured what this card could not, and the engine changed on their reports (HF discussions #1, #2 and #4). The numbers, as they sent them:

What follows from them, if you are on such a machine:

• On a 24 GB Mac the 25.7 GB file works after 0.5.79, for clips of ≤ 40 frames. The prompt encoder's pages are released after the text encode; what remains — DiT, VAE decoders and the activation cache — fits up to ~40 frames. Past that the cache spills to swap. For longer clips chain 40-frame chunks (--last-frame of one render becomes --first-frame of the next) or use the clipproj4b files, which leave the room.
• The Metal driver budgets by buffer size, not resident pages. The weight arena's overlapping windows read as ~27 GB to the driver even after the encoder is released, so the first ops after the encode page from the SSD and can take seconds. Before 0.5.80 a single such op tripped the contention kill and the rest of the run walked the CPU (>60 s a step); the kill now needs three consecutive strikes, exempts weights that were not resident, and CMF_MM_KILL=0 turns it off. If a run still says device contended, CPU for the rest of the process on a machine nobody else is using, that variable is the answer.
• The kill is disarmed during the prompt encode (0.5.80). The encoder is a one-shot pass over 12 GB of weights; on a machine the file does not fit it streams from disk, and its GEMMs run over any budget for reasons that are not contention — the report that had to gut mm_kill in the source was on exactly that. The kill now arms only when the denoise loop starts, and three strikes are still needed.
• The keyframe encode is CPU work today. With --first-frame the video-VAE encoder runs the reference picture on the host (~100–140 s on an M4 for a 448×768 frame; 0.1 s without a keyframe). 0.5.80 puts the pool's workers on the performance cores (they were landing on the E-cores with the P-cores asleep — that report's asitop), which shortens it; a device path for the encoder's 3-D convolutions is the real fix and is on the list.
• Frame budgets on 24 GB, from that user's sweep: with the 25.7 GB file 512×256 is safe to ~70–90 frames and 768×448 caps at 40–50; with the 14.5 GB v2 file 448×768 at 50 frames is the sweet spot (136 s per step) and 90 frames is where paging starts. Past those the machine swaps and the GPU stalls to nothing — better to chain clips than to push the frame count.
• The draft → final workflow. Block the shot on clipproj4b-fl2va-v2 (90 s on the Mac; v2 holds faces through a clip — "25 GB-level face consistency at 14 GB speed", that user's words), then pay the full encoder once for the final take. Identity of specific real people is still the full encoder's territory.
• --height 256 instead of 288 halves the video-VAE decode on every machine (three 256-pixel tiles instead of six).
• Voices are prompt space here, not in the release. Speaker identity, timbre, pace and emotion respond to stage directions in the prompt, and a fixed seed keeps the same actor across takes — which is how to work with this file today. But the earlier claim on this card that "H3 has no reference-audio input" was wrong, and a user was right to push back (discussion #3): the release is tagged audio-to-audio-video and video-to-audio-video, and the DiT takes both as conditioning rows. What is missing is on our side and it is not training — see What this port does not do yet.

Draft small, refine big (two-stage with LTX-2.5)

Since 0.5.100 the Turbo draft can hand its frames to LTX-2.5 for a short refinement pass at full resolution — the draft supplies composition and motion, LTX reinvents the detail:

cortiq animate mmh3-turbo-clipproj4b-fl2va-v2-q4tp.cmf \
  --prompt "…" --width 512 --height 288 --frames 39 --frames-dir draft/
# upscale the frames 2x (any bicubic) and trim to 33 —
# H3 renders 17k+5 frames, the LTX VAE takes 8k+1
cortiq ltx-video --model ltx25-q4tp.cmf --prompt "…same prompt…" \
  --video draft2x/ --video-strength 0.45 --width 1024 --height 576 --frames 33

On a 5090: draft 40 s, refine 499 s at 1024×576. A/B of the same seed is in samples/refine_ab_*.mp4. The two containers don't want RAM at the same time — run the stages sequentially. --video-strength is the dial: 0.45 keeps the draft's motion, higher repaints more.

Making it smaller

Half this file is the PROMPT ENCODER — 12.2 GB of Qwen3-VL against the DiT that actually draws. Two ways to act on that were tried, and the three clips at the top of this card are the result: squeezing the encoder does not work, replacing it does. Here is why, in both directions.

Two bits: smaller, faster, and answering a different question

The obvious next cut is the DeepSeek-V4 policy: gate/up at two bits, everything else at four. It builds — 23.94 GB down to 18.74, and with a device kernel of its own it renders faster than the four-bit file — 217.3 s against 258.4 when the pair was measured, because there is less weight to move. (Both numbers are from the build of that day; the four-bit file renders the same clip in 60.2 s now. The ratio is what carries over, not the seconds.) cortiq verify passes. The file is here.

It also stops following the prompt, which is why it is not the one to reach for.

Same prompt, same seed, same four steps. On the left the corgi is behind a pan with batter in it, drawn flat and clean, which is what was asked for. On the right it is a different animal in a different style with no pan and no pancake at all, over a washed-out ground with visible texture noise. That is not a quantizer trading detail for size; that is a model answering a different question.

The likely culprit is where the two bits landed. Half this file is the PROMPT ENCODER, and the policy put two bits on its gate/up planes along with the DiT's — so the loss falls on the part that decides what the clip is about, not on the part that draws it. A two-bit build confined to the DiT would save ~2.9 GB instead of 5.2 and is the version worth measuring next — the packer's policy is one predicate, is_wide_plane, if you want to try it. The file above is published so that experiment starts from something rather than nothing; four bits is what to render with.

A smaller encoder: replace it, don't squeeze it

The two-bit section above ends on a diagnosis: half this file is the PROMPT ENCODER, and squeezing it is what broke the prompt. There is a second way to act on that diagnosis — don't compress the encoder, replace it.

ClipProj fits a ridge regression from a small Qwen3-VL's hidden state into the space the DiT was conditioned on. Same tokenizer, same family, one affine map:

cond = ((h - mean_in) / std_in) @ W [+ GELU residual] * std_out + mean_out

mmh3-turbo-clipproj4b-q4tp.cmf is the text-to-video file with Qwen3-VL-4B tapped at layer 24 standing in for the 32B tapped at 50, plus the 304 MB projection kept exact — f32, no quantization on the piece that carries the whole substitution. Everything else is copied through byte for byte: DiT and both VAE decoders, still q4tp. Nothing anywhere is two bits.

23.47 GB → 13.16 GB. The encoder went from 552 tensors to 277.

Does it still mean the same thing?

That is measurable without rendering a frame: dump what the DiT actually receives (CMF_TE_DUMP=<path>) from both files on one prompt, and take the cosine per token.

The tap index is 0-based, and off-by-one is a real failure mode rather than a theoretical one: at 25 the worst token sits on the floor, uncorrelated. Token 0 is not projected at all but replaced by a stored sink_out — the attention sink is an outlier no regression fits — and it lands at cosine 0.9999 against the teacher's, which is the sharpest single confirmation that the mechanism is wired right.

What it buys

The one number that transfers between machines is the encode stage, because that is the only stage ClipProj replaced. Same prompt, seed and four steps, 512x288x39, measured inside one run:

Everything after that is residency, and residency is a property of YOUR card, not of this file. On the 24 GB RTX 3090 these were taken on, the whole render came out roughly half the time of the 23.47 GB file and the video VAE decode more than halved — but totals on that box drifted between 140 s and 210 s for one unchanged configuration as the card warmed, so treat the ratio as a direction and measure your own.

The point is the 20 GB card this variant exists for, where the difference is not a ratio but a cliff: a reader of this repo measured 20 minutes for one 512x288 clip on an RTX 3080 20 GB, paging the 23.47 GB file through a ~19 GB weight budget. At 13.16 GB, with a polled whole-run peak of 15.1 GB of VRAM, there is nothing left to page.

The parity probe takes the device arm on both files at the same rel rms 4.65e-3, which is its own small proof that the DiT came through untouched.

What it costs in quality

Judge it on the clip at the top of this section, not on a frame: a still catches the pancake at rest and reads as a loss that is not there.

Across the 39 frames the 4B does the whole job: corgi, chef hat, flat clean style, and the pancake leaves the surface and comes back, the dish empty underneath at the top of the toss. The verb survives — that is what q2tp lost, along with the animal and the pan.

What drifts is set dressing. The 32B renders the cooking surface as a griddle and puts patterned wallpaper behind; the 4B gives a rimmed white plate and a plain ground. A 0.92 cosine is close, not equal, and where it is not equal is the scene's furniture rather than its subject or its action.

So the ordering is not "smaller is worse". The two-bit file answers a different question; this one answers the right question with a plainer set, at 56% of the size. If you have the VRAM for the 32B encoder, use it — its framing is richer. If you are paging, this is the better trade, and unlike the two-bit build it is a trade rather than a loss.

Sound is untouched either way: the audio branch never sees the prompt encoder. The clip with its audio.

Building one

cortiq animate-pack \
  --in  mmh3-turbo-q4tp.cmf \
  --te  qwen3vl_4b_bf16.safetensors --te-layers 24 \
  --clip-proj mmh3-4b-ClipProj-celeb-mlp.safetensors \
  --quant q4tp --out mmh3-turbo-clipproj4b-q4tp.cmf

--te-layers is not a size knob, it is the tap: layers above it never execute, so packing them is pure file. --clip-proj carries the projection in exact and replaces the encoder as a whole component — matching tensor names alone would leave te.layers.24..49 of the 32B behind, six gigabytes that num_hidden_layers then excludes from the forward while disk and VRAM budget still pay for them.

The encoder is Comfy-Org/Qwen3-VL text_encoders/qwen3vl_4b_bf16.safetensors, and the projection is NicoLab28/ClipProj-MiniMax-H3 mmh3-4b-ClipProj-celeb-mlp.safetensors — use the file the projection was fitted on, since the map is only valid for those exact weights. An 8B projection is published too and scores higher on its author's corpus (0.8037 against 0.7930); it costs about 4 GB more.

What it costs to run

The file is memory-mapped, so plan on RAM at least its size or every step touches non-resident pages.

One RTX 5090, 4 steps, 39 frames. RUST_LOG=info prints this breakdown for every run:

The card is 10.7× the host path on the same machine, same seed. At 8 steps a 512×288 clip is 91.6 s; at 2 it is 42.8. The same 4-step render took 172 s when this card was written — the pipeline has since moved onto the card end to end, both VAE decoders with it.

Nearly all of the decode is the video VAE — the vocoder is 4.3 s of it. The packed sequence is [text | audio | video] and everything attends to everything, so cost grows with the token count and then with its square: a 512×288 second is five times the tokens of a 256×160 one.

A free 2× on the decoder, if you want it. The video VAE decodes in 256-pixel tiles, always, and grows the OVERLAP rather than the tile count — so a 288-pixel edge is covered by two 256-pixel tiles overlapping by 224, and you pay for 512 rows to get 288. An edge of exactly 256 is one tile. 512×256 therefore decodes three tiles where 512×288 decodes six, for 89% of the pixels. Measured on the current build: the video VAE goes 16.6 s → 8.4 s and the whole render 60.2 s → 48.5 s. The schedule is the reference's and this port reproduces it exactly; picking an edge that lands on it is free.

Host and device do not agree to the last bit, and neither is wrong. The host arm quantizes activations to int8 (CMF_SDOT) where the device dequantizes to f32, so the two renders differ by a few per cent in latent rms and visibly in fine texture. Set CMF_SDOT=0 on both sides to compare arithmetic instead of that approximation.

Why the device took a while to trust. It is no longer opt-in — the parity probe decides per file — but getting there took three fixes, and one thing is still held back.

The engine's blocked f32 GEMM cached its weight-side device buffer by pointer address. Every batched attention allocates one k/v scratch pair per call and refills it per head — same address, different matrix — so head 0's keys came back for every head, on the GPU only, silently. It is keyed on a content fingerprint now. The same GEMM also took every job over 4 M MACs on sight with no CPU arm to lose to, which on this model's decoder was three times slower than the host it displaced; it goes through the same measure-don't-assume probe as every other op class now, and on this stack the probe hands that work back (0.24 ms device against 0.13 host) while sending the weight GEMMs to the card (25.8 ms against 92.0).

Still held: the cooperative-matrix kernel runs this model out of f16 range. At 256×160 the render is correct; at 512×288 the audio stream goes NaN on the second sampling step and the video follows. Bisected — CMF_BAKE_GPU=0 does not help, CMF_COOP=0 does — so cortiq animate pins CMF_COOP=0.

That hold is specific to this model, not a verdict on the kernel: the image model on the same card and the same kernel renders 20.5 s without it against 14.8 with, and the two agree to 42.6 dB — the price of f16 operands, which the kernel documents, not a fault. MiniMax-H3's activations are simply larger. Giving that kernel a scale is the next real speedup here.

What the conversion did

The adaLN collapse. Forty per cent of the released DiT is one matrix per block: adaln_proj.linear is [96768, 2688], 520 MB at bf16, 13 B of the model's 33 B parameters — for a map whose input is one number, the timestep. Its output over the whole schedule is a one-dimensional curve in R^96768, and Comfy-Org's pruned checkpoints already ship it as one: an adaln_t_table of [1025, 8] shared by every block and per-block weights of [96768, 8].

Measured against the full matrix on block 0 (tools/mmh3_fetch.py check, which range-reads 520 MB out of the 66 GB file rather than downloading it):

adaln  max|Δ| 8.0e-4   rms 8.7e-5   against a signal of rms 0.464
time-curve singular values 1..12, relative:
  1.00e0 2.96e-1 1.05e-1 6.63e-2 6.60e-3 2.11e-3 5.61e-4 2.92e-4
  3.67e-5 2.73e-5 1.32e-5 1.34e-6

The ninth singular value is already 3.7e-5 of the first. Rank eight is not an approximation anyone should feel nervous about; the 26 GB is redundant.

The Turbo LoRA is written against the FULL matrix (lora_A is [16, 2688]), which is why the ComfyUI node re-injects the time conditioning at run time when the base is pruned. cortiq animate-pack does it once, at conversion:

adaln(t) = W_p · u(t) + b + B · (A · silu(e(t)))
         = [W_p | B] · [u(t) ; A · silu(e(t))]

— a rank-24 curve, driven by a [1025, 24] table per block. 4.6 MB a block instead of 520, with the LoRA already inside it.

The rest.

• Backbone — bf16 → q4tp, 4.16 bits a weight with a predicted per-row scale ladder. The LoRA's rank-64 update is merged before quantizing.
• Prompt encoder — Qwen3-VL-32B truncated to 50 layers, 51.5 GB → 12.2 GB. It is the largest single component of the file and it runs once per generation.
• Video VAE — decoder only. It is a ViT3D, not a conv stack: 36 transformer blocks over the latent grid and one linear that expands each cell into a 4×16×16 block of pixels. The 3-D causal CNN encoder is a third of the checkpoint and text-to-video never runs it.
• Audio VAE — decoder only, f16. Quantizing a vocoder buys 45 MB and costs audible hiss. Its 254 kaiser-sinc resampling filters are read from the checkpoint rather than re-derived — the design formula is in the code as a fallback, but a filter you compute is a filter that can drift from the one the weights were trained against.
• Integrity: 47.83 B parameters over 2 361 tensors; cortiq verify checks every one against the directory's hashes.

On parity

Established, not assumed, and separately for each of the four stacks. The reference is ComfyUI's own module, run on a toy checkpoint carrying the release's real tensor names and the release's real schedules — tools/ builds them, tools/mmh3_toy_gate.sh runs the diff. The packs are exact f32 on purpose: q4tp's noise floor sits an order of magnitude above the arithmetic difference these are looking for, so quantizing here would pass a broken port.

A dozen conventions in this model pass at one token and fail differently at a hundred, which is why the toys are not one-vector unit tests: the packed layout's cursor, the video time axis's 1,4,4,4,4 span pattern, which 96 of 128 head dimensions rotate, the adaLN row order (timestep-major, modality-minor), the video VAE's 256-pixel tiling — global attention makes a tile a different computation from a whole frame, so the tiling is part of the output, not a memory strategy — and the audio stream's separate clock.

Two clocks

The video and audio latents ride different flow schedules (shift 12 and 3). The sampler walks the video grid, which at four steps is 1, 0.973, 0.923, 0.8, 0, and integrates the audio on its own remap of it. Stepping both on the video grid is what a stock sampler does; it is fine at twenty steps and wrong at four, because over the last interval Δσ_a and Δσ_v differ by a factor of three and no per-step slope correction survives a step that large. --stock-sampler reproduces the broken behaviour if you want to hear it.

What this port does not do yet

The release is tagged for six conditioning paths. This container packs one of them — fl2va, text and/or keyframes → video + audio. What the others need is listed here so nobody has to guess whether it is a missing feature or a missing possibility. None of them needs training.

Two more, on the runtime side: the latent upscaler published for H3 (a 345 M-parameter 3-D conv net) is not ported, and there is no fused device kernel for adapter branches on this model — see below.

The eight-bit build, and what it costs today

mmh3-turbo-clipproj4b-fl2va-v2-q8_2f.cmf (26.90 GB, 26.21 B parameters, cortiq verify clean) packs the DiT as q8_2f — the two-field int8, w = q·row[o]·col[i]: eight bits with a second scale field along the input axis, which is where an activation-outlier channel shows up from the weight side. As a codec it is strictly more faithful than the four-bit ladder.

It renders on the card — after two gates were fixed, and the story is worth reading if you pack your own containers.

The first run of this file left the RTX 5090 idle at 2 MiB and took 357.3 s. Neither cause was a missing kernel:

1. The startup probe matched on Q4TiledP by name and dtype. Finding no four-bit qkv weight it declared the host path for the whole render — for a codec that has a device GEMM of its own. The two-field int8 folds its column field into the activation and what is left is the per-row int8 kernel both backends already ship. The probe now asks the tensor which entry point its codec has (QTensor::device_matmat).
2. The weight-residency budget was the whole heap minus a gigabyte. That survived only because every container published before this one had weights far under it; 24 GB of eight-bit weights took the card and the first scratch allocation died with wgpu error: Out of Memory. A quarter of the heap is held back now — 32 GB card → 24 GB of weights.

With both: 171.5 s on the same card and clip (103.3 s denoise, 62.2 s video VAE), against 357.3 s on the host, and the probe agrees with the CPU arm to 5.77e-3.

It is still slower than the four-bit file's 60.2 s, and that part is about kernels: q4tp has the fused qkv → attention → output submission and the packed FFN, q8_2f goes through the generic per-op GEMM. Fusing those for the two-field codec is the next piece of work, and it is worth roughly what the fusion is worth on q4tp.

The latent upscaler

Render small, resize the latent, decode once:

cortiq animate mmh3-turbo-clipproj4b-fl2va-v2-q4tp.cmf \
  --prompt "…" --width 512 --height 288 --frames 39 \
  --upscale minimax_h3_latent_upscaler_3d_fp16.safetensors --upscale-by 2.0 \
  --out big.avi

The net is LBH-123-AI's — 345 M parameters, twelve residual blocks and six temporal convolutions on each side of a trilinear resize, with a scalar scale embedding modulating every block. It is ported into the engine and gated against the node's own torch module on the same weights: worst 6.68e-6, relative rms 3.92e-7.

Same seed, same prompt, same denoise. On the left a resampler has nothing to add and softens hair, coat seams and the wet road; on the right the detail is generated. Measured on an M4 (24 GB), 22 frames: denoise 76.9 s, upscale 13.8 s, VAE 98.2 s — 193 s for a 1024×576 clip whose denoise only ever paid for 512×288. The upscale itself is the cheapest stage in that list.

Why it matters on a 24 GB machine: the alternative is decoding through a 5 B-parameter VAE, resizing pixels and encoding again — the expensive path — or interpolating the latent, which is the cheap path that ghosts. This is neither. You keep the frame budget of the small render and get the detail of the large one, and the file is loaded beside the container like an adapter, so it stays under its own licence.

Reference clips

cortiq animate model.cmf --prompt "…" --video ref_frames/ --video-stride 8

Every eighth .ppm of the directory becomes a condition pinned to its own moment of the render, and the source clip is mapped onto the render's length by position — a 100-frame reference conditions a 39-frame clip at the same moments, not the same indices. This is the fl2va keyframe path with more than two frames. It is not a port of the release's own v2v node, which conditions differently; what it gives you is composition and motion carried across a chain of shots, which is what the keyframe hack in discussion #6 was reaching for.

Adapters at runtime

Community LoRAs for H3 run against this container as they ship:

cortiq animate mmh3-turbo-clipproj4b-fl2va-v2-q4tp.cmf \
  --prompt "r34l1sm a woman in a red raincoat on a neon street, close-up" \
  --lora h3-realism-people.safetensors --lora-strength 0.8 \
  --out take.avi

--lora reads a .safetensors in any of the three conventions in the wild (diffusion_model.…, base_model.model.dit.…, or the bare module path), at F32/F16/BF16, with either lora_A/lora_B or lora_down/lora_up naming. It binds attn.qkv_proj, attn.out_proj, mlp.fc1, mlp.fc2 on all fifty blocks and on the two token-refiner blocks, and it prints what it bound:

lora: rank 32, 104/104 branches bound

Branches it cannot bind are named rather than dropped in silence. The one real gap is adaln_proj.linear: this container carries the modulation as a rank-24 curve over the timestep (that collapse is 40% of the released model's weights and most of why the file is 14 GB), and folding an adaLN update into it needs the time embedding, which only the packer has. Adapters that touch adaLN — the spatial-physics and streaming ones — therefore land partially, and say so. Bake them in instead with animate-pack --lora … --time-embedder …, which is exactly how the Turbo LoRA got into these files.

What it costs. On an M4 (24 GB), 512×288, 22 frames, four steps, with fal/MiniMax-H3-Realism-People-LoRA (rank 32, 104 branches, all of which bind), the two runs taken back to back with memory free: denoise 133.6 s with the adapter against 126.1 s without — 1.06×. The video VAE, which no adapter touches, moved 53.4 → 56.9 s between those same runs, so on this machine the adapter costs at or below the noise. The branch itself is half a per cent of the projection's arithmetic and rides inside the base GEMM's Metal submission; what it can cost is the attention fusion standing down, because a branch on qkv_proj or out_proj needs the panels that fusion keeps on the card — visible where the DiT is fully resident, hidden where weights stream. --lora-strength 0 reproduces the base render byte for byte.

Which parts of an adapter matter. CMF_LORA_PROBE=1 prints every branch by its measured contribution ‖s·ΔY‖/‖Y‖, and CMF_LORA_ROUTE=<r> switches off the ones below r. For the Realism adapter the loudest branch is 150× the quietest, blocks 0–2 contribute nothing it would miss, and 41 of its 104 branches carry the look:

lora branches by contribution ‖sΔY‖/‖Y‖ (41 of 104 live):
    0.1633  on   blocks.13.attn.qkv_proj
    0.0946  on   blocks.9.attn.qkv_proj
    …
    0.0011  off  blocks.1.attn.qkv_proj

Rendered on those 41, the clip still looks like the adapter and not like the base (13.34 dB PSNR against the base, where the full adapter is 13.76, and 16.75 dB against the full adapter). It did not make the step shorter on Metal — the reason, and where routing does pay, is in docs/LORA.md.

Provenance

Weights derive from MiniMax's H3 release as repackaged by Comfy-Org, and from larryvrh's Turbo LoRA; both remain under their own licences. The Turbo LoRA is a preview — its own card notes plastic-looking skin and over-sharp grain at ckpt850, and nothing here changes that. The CMF container and the cortiq runtime are Apache-2.0 (see the repository's LICENSE and PATENTS.md).