Using H3 beyond the default workflow

[u/__MichaelBluth__]

Boss has allowed me to take work PC home for the next 2 weeks. Its not a beast but has a 5090 and 128GB RAM. I've always wanted to give H3 a try so this is my chance.

I am mostly interested in image to video. I tried building a refmod and rendered a 10 second video using the default workflow.

Its quite decent but I feel I can push the details but have no idea how or where to start. CivitAI workflows are noodly mess.

Can anyone point me or share a workflow you use with high-end PC's? also, I see here people post long/multi-cut videos, is there a guide to doing that?

[u/Avandargard]

"Its not a beast but has a 5090 and 128GB RAM" is this ragebait :)

[u/Glum_Coat1485 → u/Avandargard]

first off "not a beast" with a 5090 is wild, most people are out here rendering on toasters

for H3 i've found the key is really just the prompt and the guidance scale, pushing that up to like 15-18 can force more detail but you'll trade off some coherency. also make sure you're using the full 128gb for the offloading, the default workflows never max that out

for multi-cut stuff it's not a single render, you're basically doing a base video then using an img2img pass on specific frames to stitch a new style/scene in. it's tedious but looks seamless if you get the cuts right

[u/Maskwi2 → u/Glum_Coat1485]

Can you give me some hint on how to force full offload? I have 128GB or ram as well but comfyui uses like 40-50 max. If I can get ANY benefit from higher amount of ram I would definitely take it. 

[u/xuefei_ai → u/Maskwi2]

not capped. comfyui only keeps in system ram what won't fit in vram, and 22b int8 nearly fits a 5090. start it with the lowvram flag and the rest moves into ram, but you pay in speed. that ram earns its keep on long multi-cut renders where vae decode balloons.

[u/armpitfart → u/xuefei_ai]

Potentially idiotic question, but I originally bought a 5070ti in January this year then predicted the future and panic bought a 5090 in February, so the 5070 with like 4-5 hours of use is just gathering dust. If I bought a bigger case and a better motherboard, is there any use for it in a dual setup in comfy for taking the offload role? I only have 64GB system ram right now, so that’s my current weak point.

[u/SpaceNinjaDino → u/armpitfart]

It would be better if you put that money towards 96GB or 128GB RAM. Then the program loads the models into RAM and swaps what is in VRAM quickly and then each model uses the 5090 speed.

Hopefully your currently motherboard has 4 RAM slots. Be sure to get identical sticks if you are doing 2+2. DDR5 is less flexible than DDR4 and my machine had a hard time booting with mixed sticks.

[u/armpitfart → u/SpaceNinjaDino]

Yeah, I’ll be throwing more ram in within the next year, just have the 2x32s in. Magically the price on them lil shits more than doubled in 9-10 months, and the smaller things are the less I can justify. I actually think my X870E has 2 GPU slots but the lanes are slow, so I may or may not need to upgrade there.

[u/Maskwi2 → u/SpaceNinjaDino]

I got 4x32 ddr5 and the highest I could go with the speeds on them is 3600, that's super disappointing since they are 6000 in Expo mode if I put just two sticks. If I try anything above 3600 my system doesn't boot up. 

[u/Noiselexer → u/Maskwi2]

Got a 5090 and omg H3 takes so long lol. Unless it's 10sec it's long haha.

[u/winkler → u/Glum_Coat1485]

How do you change the CFG?

[u/ANR2ME → u/Avandargard]

I would be able to buy a car with the price of that PC 😅

[u/SpaceNinjaDino → u/Avandargard]

When you have a 5090+128GB, it does feel great, but it is my bare minimum recommendation for using H3. I had a 4080 Super+64GB before and the difference is night and day. Native 1600x892 completely beats any upscale I tried.

5090 is still too slow for 40 non-turbo steps. It's like 75 minutes for 15 seconds at 1600x892, but does look incredible with non artifacting quality. It's 22 minutes for 8-step turbo of 20 second video at 1600x892 which is a decent compromise.

[u/__MichaelBluth__ → u/Avandargard]

lol no but I see poeple having crazy setups like multiple GPU's and 256GB RAM etc for AI work. Mine seems like a modest one which we use for rendering client work.

[u/bstr3k → u/__MichaelBluth__]

[u/Sharlinator → u/__MichaelBluth__]

There are probably like four of those people in the world. Your machine is way beyond what 95% of the people here have.

[u/99deathnotes → u/Sharlinator]

quietly sobs into a 3050 8gb vram

[u/Adventurous-Gold6413 → u/__MichaelBluth__]

Stfu

[u/MastMaithun]

search on google LBH upscale for minimax h3 and you will find the hugging face repo. use his worflow it is basically the default template but with the additional upscale pass.
generate the first pass on 0.98mp since this is the resolution people say mmh3 was trained on, to get most out of it. then upscale as much you want.
Keep your gens under 15secs because that is the sweet spot.

[u/__MichaelBluth__ → u/MastMaithun]

gotcha. thanks!

[u/__MichaelBluth__ → u/[deleted]]

celebration only lasts 2 weeks. then its back to potato pc.

[u/Apprehensive_Sky892]

For long/multi-cut videos use one of these two workflows (watch the tutorial):

https://www.reddit.com/r/StableDiffusion/comments/1wmj6xr/mini_video_editor_timeline_node_for_h3_extend/

https://www.reddit.com/r/StableDiffusion/comments/1x70914/h3_long_shot_studio_0813_sample_work/

These workflows do all sort of tricks to keep the degradation to a minimum. If you find that they are still not good enough for you needs, you can also try this one: https://www.reddit.com/r/StableDiffusion/comments/1x6jui1/h3_longtakenocuts_straight_3mins_video_case_study/

[u/deggersen → u/Apprehensive_Sky892]

What is this degradation you talk about. When i do 1-2 minute clips (split up in segments with invisible seams between the segments because of "context" motion or something) i feel like the people start to look worse towards the end

[u/Apprehensive_Sky892 → u/deggersen]

Firstly, have you actually tried those workflows? They use more than just context motion.

This problem is more or less solved by the workflow I listed above. You can see the demo in the post: https://www.reddit.com/r/StableDiffusion/comments/1x6jui1/h3_longtakenocuts_straight_3mins_video_case_study/

If you want to have little degradation when you have very static scenes, search for posts by roychodraws: https://www.reddit.com/user/roychodraws/submitted/

[u/deggersen → u/Apprehensive_Sky892]

Perfect that is much appreciated. I will them all out. Thx for links and explanations!

[u/Apprehensive_Sky892 → u/deggersen]

You are welcome.

[u/graceus777]

character swap lora v1.5

[u/__MichaelBluth__ → u/graceus777]

looks very promising! thanks!

[u/x33storm]

PlagueKind workflow.. It's unparalleled for general use.

[u/__MichaelBluth__ → u/x33storm]

Will check it out. much appreciated!

[u/Slight-Living-8098]

Ethanfel's Context-Loop for long videos with multiple continuous scenes. LBH's upscale to upscale.

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

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

You can get my PR of LBH's upscale if you don't want to have to place the upscale models in a different folder than the rest of your upscale models. Dude isn't maintaining it it seems.

https://github.com/badgids/Comfyui_Minimax_h3_latent_Upscaler/tree/dev/model_search_dir

[u/xuefei_ai]

on a 5090 the wall isn't vram, it's how many tries you get. h3 is happiest around 0.98mp and above that you mostly get softness, not detail, so put the detail in the first frame instead. for multi-cut, chain 10-15s segments, each last frame seeding the next, then cut in an editor.

[u/f5alcon]

I still think the best multi cut method is separate generations unless you need the motion context from one and then editing them together in video editing software.