Iray Rendering won't use GPU, uses CPU only

Succulent Fruit

Hey guys, I'm running a GTX 970 4 GB, with the latest drivers from Nvidia, and my CPU is an Intel i5-7600k. Since I started using Daz, when I render, my computer essentially locks up, because its using 100% of my CPU, instead of using the GPU. This has been for at least a year, and that means a large number of different Nvidia driver versions. I just today realized that In the advanced settings for the Iray renderer, you can turn off the CPU as a rendering option- but that did absolutely nothing- the render still uses only my CPU, and my graphics card remains idle. 

This isn't acceptable, and as far as I know, its always done this, even with my previous graphics cards. I'm running Daz Studio 4.11.

This is the history for my current render, which is only using the CPU:

Rendering in NVIDIA Iray

Compiling Shaders - 0/1

Rendering image

Rendering...

Iray VERBOSE - module:category(IRAY:RENDER): 1.2 IRAY rend progr: CUDA device 0 (GeForce GTX 970): Processing scene...

Iray VERBOSE - module:category(IRAY:RENDER): 1.3 IRAY rend stat : Geometry memory consumption: 115.942 MiB (device 0), 0 B (host)

Iray VERBOSE - module:category(IRAY:RENDER): 1.2 IRAY rend progr: CPU: Processing scene...

Iray VERBOSE - module:category(IRAY:RENDER): 1.4 IRAY rend stat : Native CPU code generated in 1.73s

 

Can someone help me fix this?

 

EDIT: In task manager, I can see that Daz is using almost all of my GPU memory, despite also using 100% of my CPU. I tried switching my primary and auxilary viewports to wireframe bounding box, to try and reduce the base amount of memory Daz uses, but it doesn't seem to work. I also tried turning OptiX off and on, that hasn't helped either. I'm assuming that my graphics card just doesn't have enough memory to run this render that I want to do.

I'm looking at upgrading to a Nvidia GTX 1660Ti 6 GB this coming week, hopefully that fixes the issue. 

Richard Haseltine

There should be more to the log than that, possibly including a failure to allocate memory if that is the issue.

Succulent Fruit

Richard Haseltine said:

There should be more to the log than that, possibly including a failure to allocate memory if that is the issue.

There doesn't seem to be any failures in the log for the render, it just appears to be using up all of the graphics memory, then loading up the  CPU as well. I fixed the main issue, where the CPU was maxing out and causing my computer to essentially lag, by using task manager to force Daz Studio to only use 2 of my CPU's 4 cores, freeing up 50% of my CPU power for other things. Unfortunately, it seems that my project idea is simply too memory-intensive for my computer to handle.

fastbike1

Your scene is too big for your Vram. 4GB won’t be enough to render a very elaborate scene without some extensive optimization. The problem isn’t with Studio or Iray. Your scene is too big for your gpu. Try to render a single clothed figure with hair. That should fit your card. 

Succulent Fruit

What card do you guys recommend for doing complicated scenes? I'm looking at getting a GTX 1660 Ti 6GB, hopefully that does the job. This is the render I eventually created from this scene:

The issue was the combination of a massive complex scenery model (the Temple of Sand, from the Daz store) and having 4 fully equipped Genesis 3 characters in the scene at the same time. By removing the complex background, and replacing it with low-poly arabian city buildings that I ported to Daz myself, I was able to reduce the draw down to just the GPU, and create this render. Another thing that helped was switching both my primary and auxilary viewports to wireframe bounding box mode, while rendering. that removed about 1.5 GB of VRAM usage.

kenshaw011267

If possible get an RTX card rather than the 1660 ti. the 1660 ti is $280 while the 2060 super is $400 and the plain 2060 is around $350. Either would be a major improvement over the 1660 ti. But if your budget is that tight the 1660 ti will be fine.

Succulent Fruit

I think I should be able to afford the 2060 Super, sounds like a great idea! 

fastbike1

@kingfisher13

If you can scrape together another $100 USD, the RTX 2070 Super is even better than the 2060 Super. Just be sure to measure your case and the GPU you are considering. Most of the 3 fan versions of the 2070 Super and above are almost 13 inches long. I haven't looked at 2060 Supers but they may be similar.

Succulent Fruit

The 2070 Super is a little out of my price range, unfortunately. Its definitely a possible future upgrade though. As for case size, that won't be a problem, I have a full size ATX case, with a HUGE amount of space for graphics cards. I'll be buying the 2060 super this week, barring any unforseen problems. Its going to take the majority of money from both my paychecks to afford it, but I think it will definitely be worth it. 

fastbike1

@kingfisher13 "As for case size, that won't be a problem, I have a full size ATX case,"

Don't take that for granted. I also have a fulle size tower and a 3 fan RTX 2070 Super will extend into the drive cage ares by about an inch.

Succulent Fruit

Its all good, there's a huge space between the drive bays and the optical drive bays in my case, that the graphics card PCI slot is in line with, I could fit the biggest GPU on the market in there, no problem. My current GTX 970 is pretty big, bigger than the standard one (I bought an OEM card from a store display model on ebay, got a really good deal on it), and it still has about 8 inches of clearance to the front wall of the case. 

JD_Mortal

For that scene... If you wish to avoid these problems until you get a better card...

1: Render the castle alone, with an ALPHA, minus the sky. (Place the sky image, as needed, with an external art program.) Why? Because the dunes don't cast any shadows on the building and the sky isn't honestly needed to be rendered within the scene, at all.

2: Render the dunes and the four models together, with an ALPHA. However, since the guys in the background are not close-up... Think about dropping the model detail, polygon count or Sub-D levels, on all models. This can further be assisted by using the advanced settings in the rendering window, related to the thresholds. Try 128:Med and 256:High, or 256:Med and 512:High. (Default is 512:Med and 1024:High.)

3: Render just the primary model, again, alone, but in high detail, with an ALPHA. Crank-up her geometry and bost those threshold values to 1024:Med and 4096:High.

4: Use an external art program to paste all the layers together. SKY, CASTLE, DUNES and Bad-guys, then the HD MAIN-CHARACTER as the top layer.

*** You may have to render a between scene, with just the dunes. (You only need her low-detail shadow, but her low-detail body may poke-out from the edges of her HD rendered body. You just add the layer without her, over the low detail layer which has her in it. Now, just erase the parts where the shadow falls onto the dunes and the parts covering the bad-guys. That will let your HD overlay blend into the dunes, without having her low-detail body poking through the edges, but retaining her low-detail shadow.)

This way, you can still change the guys locations, or add more guys, and your video-card memory will never be an issue.

They do this "layering", quite often, all the time. Almost every rendered video does this. They render a backdrop, a far-scape, a near-scape, the local-area, support-models, and primary models, individually or grouped with various levels of detail, to ultimately create the final product which is done post-render. They don't often cram everything into one scene and just hit render once, getting a single finished product. ("The matrix", "Cat woman", "Need for speed", "Fast and the furious", "Toy story", etc...)

Though, the same applies for still-images too. Why try to cram system-bogging post-processing elements into a render, when a simple post-process edit does it faster and give you more potential options, without a need to re-render the scene again?

Succulent Fruit

Excellent idea, JD_Mortal! I will definitely try that combination.

Padone

kingfisher13 said:

This is the render I eventually created from this scene

For composition some shadow catchers may also be useful.

https://www.daz3d.com/forums/discussion/57051/how-do-you-create-a-shadow-catcher-in-iray

As a side note if that's the render quality you need then you may be able to get it with 3delight without raytracing. I see no complex shadows or refractions in that image. Using 3delight without raytracing is almost a opengl rendering so it's light-speed over iray.

Succulent Fruit

Thanks for the idea, Padone, I'll try that on my next complex render! I did just order an RTX 2060 Super as well, can't wait to install that and do some proper rendering!