How to reduce memory consumption on Arnold GPU?

[Intuos5]

Yesterday, I finally got around to testing the GPU render. I've tested a scene with a simple plane and a 200k poly object with physical materials applied to both. Even though I haven't applied any textures, Arnold consumes 7,8 Gb of memory from the 8 Gb that I have available. I am therefore seeing spikes in GPU utilisation usually slightly above 40%. I am using Arnold 5.4.0 on a gtx 1070 (mobile) with driver version 431.70. Obviously there is something going wrong here, but I can't figure out what. Any ideas on taming memory consumption?

[Stephen.Blair]

Please post an Arnold log, which will show, amongst other things, where the memory is being used.

[Intuos5]

Interesting, the only tweaks I did to the scene were changing the light direction (Sun positioner) and I've rotated the model a little bit. Now my memory consumption hovers between 3,5-3.6 Gb. So unfortunately, I don't know how to evoke the behavior. Regardless, my CPU is utilised by around 80% while the GPU is around 40%. 

To give an idea about the scene:

I still find it fairly noisy after a 4:15 render time. From my experience with a Vray trial, rendering heavier scenes than this on a GPU (or in hybrid mode), this scene shouldn't have taken as long/ be as noisy. Especially considering that my GPU wasn't used to it's full capacity. I'm hoping we can figure it out, because I like the effort being put into Arnold as GPU renderer!

[madsd]

V-ray is quite a lot slower than Arnold.

If you upload that bike, Ill show you a noice free image rendered in a few seconds in 5000x3000 resolution on the GPU.

[Intuos5]

---

@madsd wrote:

V-ray is quite a lot slower than Arnold.

If you upload that bike, Ill show you a noice free image rendered in a few seconds in 5000x3000 resolution on the GPU.

---

@madsd I'm interested to see it. It is not my model, I just needed an image of a bike for other purposes. The original file can be found here. My render was 4000x3000 and took four and a half minutes. Could you let me know which settings you've used and what GPU you have? 

[madsd]

- resolution 5000x3000
- render time, 29 seconds.
- 1080ti card.

[madsd · Accepted solution]

5000x3000

13 seconds render time.

10 seconds denoise time, IntelOIDenoiser - so I render 3 files, main render and albedo and normal in each own AOV and run a post calculation on it.

[Intuos5]

Interesting, thank you for the effort. I'll have a go at it at the end of this week (when I've got more time) and will report back on the results. In addition, I'll see whether I can influence the GPU utilisation with some tweaks.  

[Intuos5]

@madsd I managed to reduce the noise at the expense of render time. The settings you've used resulted in a very noisy render for me and is on the right hand side. By increasing the amount of adaptive samples to 50 (less would have sufficed, I suppose) and by bumping up the Camera(AA) to 2 the result on the left was achieved and both were denoised. 
How come my render is much more noisy than yours using the same settings?

[madsd]

Im using a denoiser to remove the last bits of noise.

We have 2 that comes with Arnold, noice.exe CPU high quality, and OptiX which is gpu driven, fast, works good for some final shots and for all types of prototyping.

The one I am using is an intendenoiser from one of the arnold developers.

[bioclone_ax45]

Mads, excuse me for opening back this old topic, but looking you really know about Arnold GPU rendering and the denoiser, do you know for any interesting source of information about that on some website? (things like knew how to optimize stuff to avoid memory problems, how to set the denoiser etc...) I use a 1080 gtx and Im really surprised with your renders quality being that short.

[CiroCardoso3v]

One way is for you to use TX textures, because this will help you to cap the Max Texture resolution.

So even if you are working with 4K  textures, your GPU only use 2K for example.