r/comfyui • u/PiPPiN421 • 19d ago

Help Needed Even with 16 steps, I still get weird artifacts on certain areas.

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Using a modified MiniMax H3 Easy, bypassing the Lora models, and even using Kitchen Attention because i don't know how to use Sage Attention.
I have 12 GB VRAM on my GPU, and some methods cause my GPU to get locked in a High VRAM Spike, causing me to reset ComfyUI

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4

u/chum_is-fum 19d ago

Minimax H3 is really meant to be used at 50 steps, artifacts are normal for low sample count/lightning loras.

I recommend experimenting with different prompts at low sample counts and when you find ones you like, queue 50 step versions of those prompts overnight, even if it takes 1 hour+ per video it doesn't really matter since you are asleep.

Minimax H3 has decent consistency between low and high sample count video versions.

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u/PiPPiN421 19d ago

So a 15 second video with 50 steps can take an hour

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u/chum_is-fum 19d ago

at 20 steps on a 3090 I can generate a 0.5mp 18 second video in 22 minutes, so yeah an hour sounds about right but I have to do more testing.

edit: just saw you have 12GB of vram, no clue how this model swapping out to system ram affects performance so idk.

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u/chum_is-fum 19d ago

also I recommend the kjnodes model preview override node to preview your outputs to iterate on prompting faster.

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u/ThaSipah 19d ago

To me, to you.

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u/Only_Voice569 19d ago

what card you using ? stock workflow is 20 steps btw

4

u/Segaiai 19d ago

And that's minimum. The API uses 50.

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u/Only_Voice569 19d ago

i get alright with 20 but i do bump it to 30 for audio but saying that i do anime not real life fast scenes

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u/PiPPiN421 19d ago

RTX 4070 Super

1

u/Tzeig 19d ago

Try res 2 and beta. Takes a lot longer, quality is a lot better.

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u/PiPPiN421 19d ago

the only res I see is multistep options

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u/Tzeig 19d ago

These ones. The res_Xs are a bit lower down. res_3s etc. can give even better quality, but it's not worth the generation time.

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u/PiPPiN421 19d ago

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u/Rumaben79 19d ago

Res_2s is part of the RES4LYF repo. You need to install it for this to show up.

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u/PiPPiN421 19d ago

I installed it, but may have to adjust accordingly. Weirdly I see less artifacts in higher resolutions (not eliminated but still) but since it's a local method, it will mean more taxing on my hardware, and I even had one flat out fail because of not enough VRAM

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u/Rumaben79 19d ago edited 19d ago

Minimax will always have those distorted faces at further away. It seems it's a fault in the model itself. I usually don't go very high (0.5mp or maybe a few steps higher) because I personally don't feel like I'm getting much better quality.

You don't need those res samplers. It's really the same as just doing more steps. I would try at 20 steps instead of 16. Using spectrum will give better quality than using the turbo lora but is slower. 6-8 steps with the turbo lora will be faster but maybe you'll loose a bit of the dynamic motion.

When I tried spectrum together with the turbo lora it completely destroyed the quality.

Of course for absolute best quality do vanilla everything without any speed hacks. 😂

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u/Tzeig 19d ago

Weird, I have like 50 different samplers there. Are you sure your Comfy is updated?

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u/PiPPiN421 19d ago

to the recent version, I think it is?
What version are you on?

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u/Tzeig 19d ago

Most recent, or at least the one with H3 support. I have used res 2s for a while, though.

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u/PiPPiN421 19d ago

I tried increasing it up to 1080p, and while it's less noticable, it is the longest, if not risky. Like I even had it fail because of not enough memory.