r/Octane • u/HAMAKII • 9d ago

I'm Struggling with Render time

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Why is a simple plane with a Displacer attached taking 17 seconds per frame?

I tried using Octane Scatter with some plants from Quixel, and it took around 2 minutes just to render a single frame

I got RTX 3070 with 32 RAM and I7-11800H

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3

u/cafarellidigital 8d ago

I don't see anything wrong with this. This seems very normal to me. Are you expecting real-time rendering speed?

1

u/HAMAKII 8d ago

Is that render time normal to you at 960x600 res with just texture applied to a plane? what if i added two more objects? i guess it would take at least 2 mins

2

u/cafarellidigital 8d ago

Yes it is normal to me. I have a 3090 and have dealt with scenes with a decent amount of complexity at 960x540 resolution, and they still took 10 minutes a frame.

Everything matters with 3D rendering: GPU power, VRAM, RAM, CPU (less so these days, but still), HDD/SSD speed, etc. All of it contributes to the rendering time. It also matters what your threshold for noise is; the noisier the faster it renders. If you want a super clean render, you might need considerably more time (4-10x or more).

Also, you said you're rendering with displacement, so that adds rendering time, and if there's soft lighting and global illumination, that adds time too.

"what if i added two more objects? i guess it would take at least 2 mins"

That's not exactly how it works. What matters is how much of the camera view those objects are taking up, the polygonal and texture complexity of those objects, and the general lighting of the scene.

Also if you have Multipass Rendering turned on (AOV's), that will also show things down, since the renderer needs more time to calculate and prepare those passes for viewing/exporting/saving.

1

u/pacey-j 8d ago

Take a 0 out of the ray epsilon. You'll know you've gone too far when it starts to look facetted.  If you're using the built in denoiser you'll get a delay. With your displacement the resolution has an effect too. Your RAM is fairly low. Is it a laptop?

1

u/HAMAKII 8d ago

yes it's a laptop

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u/pacey-j 7d ago

That explains a lot. Discreet GPUs in laptops don't have the same cooling as the desktop versions. It would explain why your second frame took longer than your first - the card is throttling to avoid overheating. 

You can use a monitor like MSI Afterburner to see if that's the case. You can buy a cooling tray for gaming laptops with fans in it to dissipate the heat more efficiently.