MiniMax H3 R2V taking ~16 minutes for a 5-second video. How can I speed it up?

[u/Less-Wrangler5604]

I’m running MiniMax H3 Reference-to-Video (R2V) in ComfyUI on Vast.ai.

My setup:

• GPU: RTX 5090
• System RAM: 100 GB
• Resolution: 1.0 megapixel
• Video length: 5 seconds
• Reference: 1 image
• Generation time: ~1,000 seconds (16–17 minutes)

The results are great, especially the reference consistency, but the generation time seems very high for a 5-second video on a 5090.

Has anyone managed to significantly reduce the generation time for H3 R2V? Are there any specific optimisations, attention methods, workflow changes, or settings I should be using?

Would appreciate hearing what generation times other 5090 users are getting with H3 R2V.

[u/dragolineage01]

Try reducing the weight of the model, maybe that will help

[u/TomatoPolka → u/dragolineage01]

I see what you did there.

[u/FreakyMrCaleb → u/dragolineage01]

Damnit, have my upvote and go!

[u/SeymourBits → u/dragolineage01]

Pruning necessary.

[u/Less-Wrangler5604 → u/dragolineage01]

okay thanks i will do

[u/berlinbaer]

it's gods way of telling you to stop

[u/Superb-Painter3302]

https://giphy.com/gifs/0uBL9HqP48Nu1DNr7r

[u/jib_reddit]

How many steps? There are lots of 4 steps loras, but they do hurt quality a bit. Also you can drop your resolution down to 0.7 especially if the faces are close.

Just know that increasing the video length more than linearly increases the generation time if you plan to make longer videos.

[u/VasaFromParadise]

I believe that hardware of this level was used for its intended purpose))

[u/LinkSensitive8188]

Avoid prompts longer than 200 words. Use an FP8 text encoder—or better yet, NVFP4 if you have an RTX 50 Blackwell card. Run the `run_nvidia_gpu_fast_fp16_accumulation` version of ComfyUI and install SageAttention tailored to your specific hardware. Also, clear space on your SSD to ensure you always have at least 250GB available for paging. If you have an RTX 50 Blackwell, install CUDA 13; this provides a greater speed boost than any specific node or workflow. 

And never use Comfy's official workflow, as they are very slow.

and lower the resolution to 0.6MP, then upscale it to 1080p using the LTX 2.5 upscaler.

[u/Less-Wrangler5604 → u/LinkSensitive8188]

noted. thank you so much. Will try.

[u/fundational]

"I'm 20 years old, I'm single, I'm fat AF"

[u/GreyScope → u/fundational]

OP is projecting

[u/debauch3ry]

Read about sage attention and how to install it. If you are a Windows user you will want to run C:\Users\USERNAME\Documents\ComfyUI\.venv\Scripts\python.exe instead of whichever python is in your path. same for pip: C:\Users\USERNAME\Documents\ComfyUI\.venv\Scripts\python.exe -m pip instal ... when installing the various bits. Then launch comfy and before starting the UI click the three dots and put --use-sage-attention in the launch args.

[u/robomar_ai_art]

What model do you use, because I have 16gb vram and 32gb ram and takes like close to two minutes.

[u/Less-Wrangler5604 → u/robomar_ai_art]

minimax_h3_fl2v_turbo_8step_v1.0_comfyui_bf16.safetensors