How to stop Blender Crashing during Rendering?

I have what I thought was a simple scene. Only 20k faces. I’ve played with the light bounces and samples to try to get to the bare min i need to get a good image and I use the denoiser, but blender frequently crashes. These are my specs

Intel© Core™ i7-7700 CPU@ 3.60GHz × 4
GM206 [GeForce GTX 960]
8gb ram

Is my hardware really bad? Or is there something I can do to my file to help? This has me worried about ever doing anything more complex in blender if I can’t render some thing like this! I’m not even using anything fancy like SSS.

Is there a way to tell blender to take longer to render but don’t crash?

file.blend (3.5 MB)

It took a century before it rendered the first tile. I changed it from branched path tracing to just path tracing and it behaved normally.

I tried removing items one by one to see how much faster it rendered. I have hidden all of your glowing objects (both visibility and render) and I cannot see them in the viewport but when I render I still see “something” that looks like the same shapes but not glowing and not being lit by the other lights in a way I would call “normal”.

edit: ok i see now, you have other shapes parented to the top level shapes.

Ok I’m guessing your materials are just very slow to render. It seems you have a main light source that is an emission within another object that is translucent. Try finding a way to “fake” the look you want and it should render a lot faster and not crash.

I have not used the translucent shader much myself but I think I remember seeing many times when people used it mixed with a diffuse shader instead of by itself.

Thanks! I’m going to try putting a spot light inside and see if that helps. I did the branch path tracing in order to help with the emission on the mesh light.

I’m glad to know it’s not just my hardware because I didn’t want to upgrade

Reduce the scale of tiles of rendering, or reduce the image resolution.
Or Go to your taskhost and increase the “ram priority”(that’s is dangerous).

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Do you have a reference image of the look you’re trying to achieve?

Are you working on a still shot or an animation?

I think a point light inside the shapes will render faster and less noisy than the emission shader but there’s probably still a much faster way to get something close to the look you want.

Also I think there is something special about the translucent shader (or maybe it was subsurface scattering?) where it behaves differently depending on if the geometry has thickness or not. In my render I added a lot of thickness via the solidify modifier.

Yes this is my reference. Was going to add the texture later but want to get the translucency and light good first.

Is reducing the tile size good if I’m doing GPU rendering? I heard that bigger tile sizes are good for GPU and smaller good for CPU

There is a built in add-on named auto tile size. Activate that and it will set the best tile size for your hardware.

big tiles is very good for GPU , but sometimes you need a good memory to support