Any tips for kicking Iray in to gear?

globally

Im running a laptop 3060 and only have about 6 or 8gb of ram so i often reach the limit and iray refuses to do nothing but cycle the progress bar. Hiding items or even deleting everything but the 4k hdri, or switching to smooth shaded and back again do nothing. I generally have to save or create a save (annoying when you just want to quickly try something out), quit out, quit the process and relaunch. There must be a better way? Seems to be a little worse for this with 4.21.

PerttiA

6 or 8GB's of RAM or VRAM?

If you really meant 6 or 8GB's of RAM, you need to get more. 32GB's is about the minimum, but if one is careful enough, one could work with 16GB's

globally

PerttiA said:

6 or 8GB's of RAM or VRAM?

If you really meant 6 or 8GB's of RAM, you need to get more. 32GB's is about the minimum, but if one is careful enough, one could work with 16GB's

 

Yep just checked, 8GB. Its what i got so i have to make do. I rarely have much more than a single character, an hdri and maybe a prop.

PerttiA

8GB's of RAM or VRAM?

RAM is the main memory used for running the OS and applications in your computer, VRAM is memory on your GPU

globally

PerttiA said:

8GB's of RAM or VRAM?

RAM is the main memory used for running the OS and applications in your computer, VRAM is memory on your GPU

My fault completely then, i have 8GB of vram. That is where iray is loading this stuff right?

hansolocambo

With 8GB of VRAM, use the GPU for Iray preview while working on a scene. But to be sure that the rendering is be done (working on complex scenes) and to avoid any problem during the CPU Fallback, simply uncheck in Render Settings > Advanced > Hardware: CUDA.  And tick only CPU. This way you can render at night, with your CPU cores + RAM, and everything works perfectly well.

CPU + RAM + eventual Swap Disk, and you can render Avatar at home. There's no limit.

GPU + VRAM .... and there's a huge limit to creativity. Iray being not an hybrid rendering engine (such as Renderman XPU™) there's no way around those terrible VRAM limits. If your scene fits the VRAM you have access to the Graphic Card immense power. If it doesnt, then be happy that we have multi-core CPUs to do the job.

GPU rendering is all very exciting, 50 to 100 times faster than CPU rendering : but it's still a tech in its infancy. Avatar required 35000 CPU cores to render and 104TB or RAM. Inside-Out required 24000 CPU cores to render, etc. In the animation Industry, CPU cores are the way to go because scenes are huge. GPU is attractive, but it is still not a suitable technology for pre-computing complex 3D scenes.

GPU is to 3D what Unreal Engine is to cinema: a great way to get a quick preview of what the final product will look like. But for the final stages: CPU + RAM remains the only reliable/possible combination these days.

You just have to live with that in mind. When your 8GB of VRAM, or 32 or 64GB of VRAM just isn't enough? Accept the fact that CPU+RAM is still the only king of complex 3D scenes.

globally

hansolocambo said:

When I had 8GB of VRAM, I used the GPU for Iray preview while working on a scene. But to be sure that the rendering would be done (working on complex scenes) and to avoid any problem during the CPU Fallback, I simply unchecked in Render Settings > Advanced > Hardware: CUDA.  And tick only CPU. This way you can render at night, with your CPU cores and everything works perfectly well.

CPU + RAM + eventually Windows Swap Disk and you can render Avatar at home. Sure it's gonna take time, but there's no limit.

GPU + VRAM + .... nothing at all. Iray being not an hybrid rendering engine (such as Renderman XPU™) there's no way around those terrible VRAM limits. If your scene fits the VRAM you have access to the Graphic Card immense power. If it doesnt, then be happy you have a multi-core CPU to do the job.

Learn to optimize things in your scene if you really want to go for GPU. Or be patient and choose instead the still attractive CPU/RAM combo that has been around for many years.

This frenziness around GPU is the same for Marvelous Designer. Sure GPU simulation is insanely fast. But at the end CPU remains the best way to get a perfect result. 3D has been around for much longer than GPUs, and coding is much more thorough around CPU optimizations than GPUs. It's all very exciting, but it's still a tech in its infancy. So let's enjoy CPUs for a few more years.

Avatar required 35000 CPU core to render and 104TB or RAM. Inside Out required 24000 CPU core to render, etc. In the animation Industry, CPU cores are the way to go because scenes are huge. And if GPU is attractive, it's just not at all a tech for complex scenes.

GPU is for 3D what Unreal Engine is for the cinema : a great way to get a quick preview of what the final product will look like. But for the final steps : CPU + RAM remains the only trusted/possible combo nowadays.

Just gotta live with that in mind. When your 8GB of VRAM, or 32 or 64GB of VRAM are not enough ? Just accept the fact that CPU+RAM is still very much the only King of complex 3D scenes.

 

So perfectly put.

My cpu is also a pile so i will continue to try and cram the gpu full when i do a final render, but i do like the cpu for viewport idea though. At least then i can preview and build my scene and then do all the usual tricks to get the sizes down before rendering.