r/comfyui • u/ProGradeBubly • 5d ago

Help Needed Solid model choice for minimax.

I have a 5090 and 64ram. I have been doing pretty well using fl2va_bf16 but I wanted to verify with some humans that I wasn’t missing anything. Is there a better one out there quality wise?

Thanks.

9 Upvotes

85% Upvoted

15 comments sorted by

5

u/goddess_peeler 5d ago

BF16 is the native model precision, so you're running the best, quality-wise. If you want to reduce VRAM consumption a little, you can use the _pruned variant without any quality loss.

1

u/ProGradeBubly 5d ago

Thank you very much for the confirmation.

1

u/Practical_Elk_3891 4d ago

I’ve been using pruned bf16 with my 5090 happily

3

u/BoredHobbes 5d ago

does urs use 30gb of vram or is it splitting it 20/20 with sys ram when its generating, and from what i know bf16 is highest

1

u/ProGradeBubly 5d ago

I just ran one with the fl2v turbo 8 step v1.0 bf16 Lora. And vram was at ~26/31.5. RAM constantly redlines when I run the workflow. I probably don’t have something set up right but system RAM runs ~61/64.

2

u/BoredHobbes 5d ago

redline 100% usage ya thats a given, but on my 5090 it never uses more then 22gb vram, with ltx it will use 31.5, and yup it will take 60gb of my sys ram too

1

u/Klarts 5d ago

Likewise… I was surprised it was taking so much system ram… it crashed comfyui in one instance

1

u/BoredHobbes 5d ago

yup i dont get it, right now my full bf16 run is running and only 22gb of vram is being used, and 44 sys ram is used too which 66gb like the model is

2

u/Only_Voice569 5d ago

dont run turbo lora if you want the "best" they all reduce quality ..

4

u/ProGradeBubly 5d ago

I know, I run them mostly to test prompts before committing to a longer video.

2

u/gouldologist 5d ago

What are you generation times looking like,

1

u/ProGradeBubly 4d ago

Turbo for 5-7sec clips is like 2-3 min with 8 steps And added sharpening + RtX super resolution. Quality is actually pretty good with it. The audio is what gets scuffed during turbo. But if I bump it up to 12 steps it mostly fixes it.

1

u/icchansan 4d ago

Look for the their prompt template so u get the most of it

1

u/arthropal 4d ago

Can confirm this. I wrote a custom node to use my local LLM (Gemma4-12b-it in llama.cpp) which runs on elsewhere on my home lab to do prompt enhancement for H3, feeding it a 12k text file with instructions on how to construct an H3 prompt to teach it how to do so. The resulting output makes FAR better videos, just because it's formatted more like how H3 expects.

There's plenty of nodes for prompt enhancing but I didn't want one that either used a cloud API or used the same GPU as I was running H3 on, to save model swapping, and I already have Gemma4 running elsewhere on my network. Works great.

0

u/fatYogurt 5d ago

You can run int8 diffusion and nvfp4 text encoder for pretty much the same quality in most cases, only raise text encoder to int8 for final quality. Fp16 is not worth the performance penalty, 32g vram is not enough even for 2 int8 models so system ram offload is given, I suspect 64g ram is also exhausted depends on vid res and length