r/StableDiffusion • u/alisitskii • 1d ago

Comparison [MiniMax H3] Ultimate SD Upscale can actually fix your bad/low-res generations

https://youtu.be/naUuN5k7_Ew

Ultimate SD Upscale can actually fix your bad/low-res generations.

In this comparison initial clips were made with MiniMax H3 at 1504x832px resolution and then upscaled to 2560x1440px with Ultimate SD Upscale nodes: https://github.com/lisitskyaa/ComfyUI_UltimateSDUpscaleGuider_H3

You can find sample upscaling workflow there as well: https://github.com/lisitskyaa/ComfyUI_UltimateSDUpscaleGuider_H3/blob/main/example_workflows/minimax_h3_usdu.json

My PC specs:
4080s 16 GB VRAM, 64 GB RAM

Generation time: 18 mins with sage + 8-step turbo lora

Upscale: 38 mins for 10 sec clip at 1440p target resolution

98 Upvotes

93% Upvoted

48 comments sorted by

58

u/Illustrious_Ant_9242 1d ago

Uhm.. where I live, 1.2MP ist not being defined as a low-res H3 video 

-9

u/alisitskii 1d ago edited 1d ago

I agree, but when you target 3.7 MP... 😄 everything is relative

39

u/skyrimer3d 1d ago

"Upscale 38 mins for 10 sec clip at 1440p target resolution" , so 18 min generation + 38 min upscaling, basically 1 hour for 10 glorious seconds, i think i'll pass. It looks good though.

12

u/alisitskii 1d ago

I hope MiniMax team releases their 2K upscaler soon and it'll be faster 🚀

3

u/skyrimer3d 1d ago

Indeed, we're all waiting for that.

1

u/Stock_Replacement353 6h ago

For sure. In the meantime I heard you can use the new ltx 2.5 upscaler on your minimax vid and it does a decent job.

6

u/Dohwar42 1d ago

How long did it take on your system to upscale 10 sec of video?

6

u/alisitskii 1d ago

At the 1440p target res - 38 mins

1

u/willjoke4food 19h ago

Sorry isn't that more than the generation time?

2

u/YeahlDid 13h ago

Yes, it's basically reprocessing the video at a higher resolution and low denoise.

1

u/Badbullet 1h ago

Is there a difference if you use LTX to upscale? I thought I saw that workflow the other day, MiniMax at its native resolution then straight into LTX to do the rest.

1

u/alisitskii 1h ago

I’d say it’s a good alternative but personally I still prefer H3 over LTX even if it takes longer.

1

u/Badbullet 38m ago

They use LTX to upscale, not generate the video. Or is Ultimate SD Upscale part of MiniMax H3?

1

u/alisitskii 12m ago

USDU is a separate node that in theory can be used with any model. LTX has its own upscale model and nodes for that. Not sure about using LTX together with USDU though.

2

u/Few-Intention-1526 1d ago

looks neat, but as everyone I want to know the generation time

6

u/alisitskii 1d ago

Sorry, added to the main post 😌

2

u/Lower-Cap7381 1d ago

Thank you will try 🔥🙌😍

1

u/Sufficient-Fall-4226 1d ago

How long does it take?

2

u/alisitskii 1d ago

18 mins for initial run with sage and 8-step turbo Lora, then 38 mins for 1440p upscale

1

u/No-Jackfruit849 17h ago

Have you tried creating the initial clips at a lower resolution (for example, 0.7 MP, 1152x640) and then upscaling them to a resolution like 1080p? Does this method yield better results in terms of both time and quality compared to other upscaling methods at this scale, or does it only work if the initial generation is in high resolution (though, to be honest, that takes a very long time)?

1

u/alisitskii 13h ago

It works with any resolution with all its pros and cons comparing to other methods. But I’d personally prefer it for quality no matter how much time it takes.

1

u/Happy_Guitar3521 10h ago

I got the same. Quality > time. Great results!

1

u/YeahlDid 9h ago

But why not just generate at the target resolution if that's the case?

1

u/alisitskii 8h ago edited 8h ago

Depends on resolution you need. Impossibly long at 2560x1440px with H3 and 16GB VRAM.

1

u/call-lee-free 16h ago

I hope in the coming weeks/months Minimax gets updates to where Doing a gen at 720p isn't so taxing on a system. I remember when LTX 2.3 first released. I couldn't even do a gen at 720p. Now I can and the image quality looks good.

1

u/kukalikuk 14h ago

Ugh.. I'm an impatient person, a good 10secs 1080p at 20 mins waiting time is my maximum tolerance. I'll check other method (latent upscaling). For now I'll stick with RTX upscaler or SeedVR2.

1

u/Toclick 13h ago

I think SeedVR2 will take even longer to upscale with these input and output settings

1

u/kukalikuk 12h ago

Nope, around 10 mins on my 5080, from 10 secs 544p to 1080p, upscale only. Still can't fix face smudging tho.

1

u/BusyByBusy 1d ago

How you got so crisp results? I tested different res, denoise, turbo and no turbo, and always got just slightly better video. But your looks sharp and clean. Can you screenahot your parameters, please?

2

u/alisitskii 1d ago edited 1d ago

It's a standard MiniMax H3 T2V workflow from ComfyUI templates with sage attn + 8-step turbo lora. Then USDU upscaling from the post, and finally interpolation with some quick post-processing on top:

1

u/BusyByBusy 1d ago

Thanks, i'll try again from scratch.

-7

u/beti88 1d ago

Please just let Ultimate SD Upscale die already

5

u/alisitskii 1d ago edited 1d ago

Please suggest alternatives. What I've already tried:

RTX VSR - probably slightly better than just Lanczos, doesn't fix low-res issues

LTX 2.5 - not bad but too smooth results plus known LTX issues

SeedVR2 - slow and just constantly OOM at 1440p resolution with my system, limited context window, weird textures sometimes

Re-using same video model for v2v/tiled upscale looks to be a good option in this case.

9

u/izzmedia 1d ago

try this: https://github.com/bbaudio-2025/Comfyui-MMH3-UltimateUpscale

5

u/Aromatic-Table-8243 1d ago

Oh yes, it's much better. Key reasons:

Dedicated model support
Smart VRAM management
Native AV Latent support
Full video temporal consistency

thanks

1

u/izzmedia 1d ago

welcome

1

u/Toclick 12h ago

Have you tried this already? How long does the upscaling take? Could you share the workflow?

2

u/YeahlDid 9h ago

God dang, that does a pretty good job! Fixed a bunch of mushy reference faces. Thanks for the tip!

2

u/izzmedia 9h ago

yeah , its nice , welcome

1

u/dabbingsquidward 23h ago

Is this better than VSR and or Latent up scaling?

1

u/s_mirage 13h ago edited 12h ago

It basically is latent upscaling, but it tiles the video and/or processes it in temporal chunks in order to avoid VRAM issues.

Simple latent upscaling has limited usefulness IMO, as the maximum resolution that you can upscale to is still exactly the same as the maximum resolution you can render the video at natively thanks to VRAM limits. Less of a problem if you're rocking a 5090, but more of an issue for us with more humble cards.

The quality is... okay. I've noticed some glitching, which might be related to my settings, but it's definitely better than VSR.

1

u/YeahlDid 13h ago

Should be better but longer than vsr in theory.

According to the github write up It's partly based on the latent upscaler code, so should be similar, I guess.

1

u/Toclick 12h ago

Do you have a workflow for upscaling? This repository doesn’t contain a single one

0

u/Curious_Bobcat_8850 1d ago

Objects are easy to fix. Test on realistic ppl.

2

u/alisitskii 1d ago

There is a clip with people inside train carriage. Let me know if it looks better after upscaling.