GPU texture consumption with Iray

sagoru

Hello everybody! How can I reduce the gpu consumption on a simple scene like the image attached? I measured the consumption with GPU-Z and it showed me about 2500 Mb... is it possible??? I'm doing something wrong? The character used in this scene is Finley HD, and without any clothes, hair or any other props it weight of the GPU is 2300 Mb. How can I reduce the weight??

fastbike1

W/ naked Finley (no hair, clothes) base HDRi, I show 2083 MB (about 500MB before render loaded).

A rough check of 8 more characters, both HD/non-hd and G2F/G3F shows a rough average of 1800MB, range from 1631 to 2083. Note that there was no significant difference between HD / non-HD for a character.

Sub-D may be a possible spot to lessen memory.

Renomista

IMA estimates around 1700MB VRAM Usage for naked/hairless Finley only. She has 5 Normal Maps and SubD Level 2

sagoru

Thank you for your answers!!! So apparently there is nothing wrong, but how can I reduce this consumption? If:

1. I change the jpg compression of a single image texture by exporting again from an external program like Photoshop
2. I change the jpg size of a single image texture by exporting again from an external program like Photoshop

it will works? There are no others ways?

If I reduce the Render SubD (Minimum) from 2 to 1 (or 0) the reduction is useless :(

gonzohot

Hi!

I jump on the subject after some test renderings with iray I've recently done:

I use a bi-xeon E5 Workstation (32threads) with two GTX titan 6GB and two GTX 680 4GB. Both CPU's and GPU's are used to render with Iray...

 

So...

 

A basic Victoria7HD dressed with hair give's me around a 2500Mb graphic memory consuption.

Adding a second character increase to 3500Mb !

Activating optix Prime acceleration make memory consuption jump to 6000Mb !!!  So it make my two GTX680 4Gb useless at the same time ! Also after rendering the used memory still locked and I have to restart Dazstudio in order to get my graphic memory back... possible bug ?

In conclusion from my tests Iray is very memory consuming. I hope the developers can fix this because not everyone can buy expensives GTX titan X 12Gb rigs !!!

I'm also facing render errors in the final Iray rendering (clothes not perfectly matching characters and giving me "holes" with skin appearing in some places...).

It's very strange because everything's ok when rendering in the viewport... if anybody knows how to fix this ? Anyway I'm gonna open a new thread for this...

 

See you and have a good day !

Tobor

Iray has a texture compression feature built into it, and nVidia suggests it gives better results than simply downsizing the textures, or (worse) picking a higher compression ratio for JPGs. At least it's worth a try.

To adjust the compression ratios, click on the Advanced sub-tab in the Render panel. The values for Medium and High Threshold are at the top of this panel. See this blog post for some ideas.

http://blog.irayrender.com/post/54506874080/saving-on-texture-memory

Tobor

gonzohot said:

Activating optix Prime acceleration make memory consuption jump to 6000Mb !!! 

There is some debate whether Optix Prime is really doing much at all for traditional quad geometries, seeing how the feature is designed to hint ray paths to tri intersections. (Perhaps there's some internal conversion going on?) I realize some have reported a speed increase -- I don't see much of a difference myself -- but I have to wonder if it's worth the extra memory. 

fastbike1

I'm also in the camp that doesn't see any useful speed increase with Optix Prime.

mjc1016

One way to test Optix...compose a scene, then convert the entire thing to a prop.   Render.

Then under Edit > Object> Geometry > Triangulate.  Render again

Tobor

fastbike1 said:

I'm also in the camp that doesn't see any useful speed increase with Optix Prime.

I think it's because you and I have been using the Optimus Prime setting instead, and as we know, that was killed off or made inactive a while back by the Megatron feature.