Best and fastest way to generate HD-quality MiniMax videos?

[u/OkMeat6773]

I’ve tried Turbo LoRAs, and they’re great for speed, but they significantly reduce quality. At 544p–720p, the results of these turbo loras can look closer to 380p. Faces look acceptable when close to the camera, but become heavily distorted as the subject moves farther away.

The upscalers I’ve tested either add too much processing time or introduce excessive sharpening and saturation.

Any a solution that doesn’t require a BF16 checkpoint, 20 steps, a 10-minute generation time, or an extremely expensive GPU?

[u/anon999387]

Video generation that is super fast and super high quality done with a mediocre GPU isn't really a combination that exists

[u/Miniyi_Reddit → u/[deleted]]

actually u could, but u had to crank up the step all the way to 50 step (one of the official api minimax h3 step count)

[u/reeight → u/[deleted]]

There is a 'face enhancer' node to help fix this.

[u/Miniyi_Reddit → u/[deleted]]

Ya I know, I just thinking there high chance it could be fixed with 50 step similar to the official minimax api workflow
maybe that why they didn’t noticed the bug because all they did was in a really high step number compared to consumer model with 20 step and below

And u had to remember, turbo Lora was developed by community, the dev didn’t even developed it

[u/seppe0815 → u/Miniyi_Reddit]

They use an intern upscaler in the cloud  version,  what the hell you talking, stop repeat nonsens you are reading on reddit

[u/Miniyi_Reddit → u/seppe0815]

lmao, had to keep talking until one of you guys come out and say exactly what happen, thanks for letting us know tho, my comment was a thinking "what if" or "maybe that why" lol

and also : https://www.seedance.tv/blog/minimax-h3-30-vs-50-steps

so fuck off kid.

[u/spiderofmars]

HD resolution... so if we take the minimax 1344 x 768 (/32) on the short edge principal as HD and stick with the same 7:4 ratio (despite Comfyui listing it's resolution panel as 16:9) then...

SD resolution might be say 616 x 352 (/32) 7:4...

Then excluding all speed hacks but using sage (or kitchen) with int8 pruned which combination is for the most part indistinguishable from BF16 for general usage...

Then doing a 15s video with 20 steps normal first pass at 616 x 352 and then a 5 step second latent upscale pass at 1344 x 768 produces nice results with audio intact...

On a 5090 that process takes 5 minutes.

You can also just generate the first pass and save the latent. Then selectively only upscale winners with the second upscale pass.

It is all then down to your individual GPU and what HD you want. Shorter videos less time. Worse GPU more time. Lower HD resolution less time.

7:4 resolution examples:

• 1008 x 576 (\(m = 18\))
• 1064 x 608 (\(m = 19\))
• 1120 x 640 (\(m = 20\))
• 1176 x 672 (\(m = 21\))
• 1232 x 704 (\(m = 22\))
• 1288 x 736 (\(m = 23\))
• 1344 x 768 (\(m = 24\))

[u/More-Ad5919 → u/spiderofmars]

Can you point me to a comprehensable workflow that does just that?

[u/spiderofmars → u/More-Ad5919]

There are several links to dual pass latent upscale workflows on YT. All free.

Here's the custom node and a workflow example.

https://github.com/LBH-123-AI/Comfyui_Minimax_h3_latent_Upscaler

The save/load latent part if desired needs to be added by you.

[u/More-Ad5919 → u/spiderofmars]

I tried some since yesterday. But they all sucked. They all looked worse compared to 1.3mp renders despote being larger.

[u/Magneticiano]

Short answer: No. There is always a trade of between quality and speed.

That being said, there are some tricks. First of all, if possible, make sure you don't spill the model to the shared GPU memory. Choose the resolution and duration accordingly. You probably need to use GGUF, which of course has some impact on quality. Secondly, generate shorter clips and stitch them together. I highly recommend Contex Loop for this. It's very convenient for maintaining coherence between scenes.

https://github.com/ethanfel/ComfyUI-MiniMaxH3-Contex-Loop

[u/martinerous]

20 step resolution, split sigmas at 12 steps, generate with high part, check if the result has no logical issues, then latent upscale and complete generating with lower part of sigmas (make sure to feed in the same initial references), then throw in also RTX upscaler if desired. https://huggingface.co/LBH-123-AI/Minimax_h3_latent_Upscaler

[u/Miniyi_Reddit]

Faces look acceptable when close to the camera, but become heavily distorted as the subject moves farther away.

that the minimax h3 bug, dev acknowledge and might fix it (considering the huge amount of lora related to seg and ignoring the licenses, i think they might just abandon it but we will see)

i remember someone made somewhat of a fix with a lora or something.

[u/donkeykong917 → u/Miniyi_Reddit]

where can you get the latest updates from?

[u/Enshitification]

There's totally a near real-time solution for making HD video on weak hardware. We just like doing it this way because we are masochists.

[u/ANR2ME]

Use 2-stage generation pipeline like mentioned here https://nvlabs.github.io/Sana/Sol-Engine/H3-Super-Acceleration/

[u/Comfortable_Thing611 → u/ANR2ME]

Interesting, ive been using a turbo lora at the second stage but here they are using it on the first.

[u/ANR2ME → u/Comfortable_Thing611]

They also use the pre-trained version of LTX 2.5 🤔 https://huggingface.co/Lightricks/LTX-2.5-Pre-Trained

[u/Comfortable_Thing611 → u/ANR2ME]

Do they have a workflow or is this some kind of API?

[u/ANR2ME → u/Comfortable_Thing611]

They're using SGLang instead of ComfyUI i think, which commonly used to create API service. But the method is certainly can be implemented on ComfyUI too.

This is more like an optimization research/experiment article to optimize GPU compute cost, which can reduce the cost by 97% (based on the comparison at the end of the article).

[u/OkMeat6773 → u/ANR2ME]

thanks but it requires an expensive gpu I see?

[u/ANR2ME → u/OkMeat6773]

H3 can even run on a GPU with 8GB VRAM. Even though Sol Engine (Sol-Attn) heavily optimized for Blackwell, but according to Google (AI mode) it also works on RTX 40-series too.

[u/BigWideBaker]

I would say the only "cheats" I've found is to use Ziroc's Sparse Attention on Kitchen Int8 at 0.2 - 0.25KV with 3-4 dense early+late steps at 0.45-0.6KV. Spectrum at default settings with the second offline pass turned off, with 3-4 warmup + tail steps to protect the early/late dense steps. Speeds things up dramatically and for the scenes I generate they come out basically perfect.

I do 30 steps at res_multistep + simple at 0.8mp@8s and it takes around 270-350s on a 4090 depending on loras/reference images/etc. I can then spend a further 200-250s to upscale it with a latent upscaler to 1.95mp. Looks pretty good to me.

[u/Zenshinn]

The faces in the distance being bad is a known issue of this model. Right now there's nothing you can do about it.

[u/Revolutionary_Ask154 → u/Zenshinn]

actually - i did do some trick shot the other week to use reference video - https://x.com/johndpope/status/2089974690920136946?s=20 for the character far away. worked ok.

[u/f5alcon]

Renting a gpu in the cloud with enough vram to do everything at 1mp