RTX 3080 TI vs RTX 3090

[kunal_gupta]

I'm looking to purchase a new GPU and can't decide between these two options. What's the Vray rendering speed difference between RTX 3080 Ti vs RTX 3090?
The data on OctaneBench suggests 3080 Ti might be more bang for the buck?

https://render.otoy.com/octanebench/...0%20%28RTON%29
https://render.otoy.com/octanebench/...i%20%28RTON%29

[Karol.Osinski]

Performance wise it might be better bang for the buck. But you are will be missing a lot on memory...

[kunal_gupta]

Hey Karol, can you please elaborate on how the 12GB vs 24GB memory affect the Vray rendering?

I'm assuming a larger memory allows the GPU to render larger and more complex scenes?

[oglu]

I feel everything below 16GB of vram does not do it. There are to much scenes i cant render.

[Karol.Osinski]

Hi kunal_gupta , in order to render with GPU your scene must fit inside your GPU's VRAM. That included all textures, geometry and such.
There is a work-in-progress feature called Out-of-core which can move resources to your RAM instead but I would not rely on it just yet.

After all it all depends of what type of work you do. I think 12GB of VRAM is totally fine if you are working on things such as product shots, car shots etc. - small scenes in general.
When it comes to Archviz and have let's say LIVING, DINING and KITCHEN in one scene to render together, it might be already a problem to fit the scene inside 12GB of VRAM.
Bear in mind if you use your GPU is connected to the display - this can already take up few gigs of VRAM and you are left with much less for your render.

If you don't feel like you are very efficient with your scenes, for example you often use much higher texture size then necessary, not using much proxies or tend to use a lot of displacement etc. then I would recommend spending few hundred bucks more for a peace of mind and get yourself 3090

[kunal_gupta]

Karol.Osinski makes sense, thanks for the insight!

[Micha]

I use one 3090 and two 2080ti. The advantage of the 24GB VRAM are for me: I can use the 3090 for system display plus rendering and the 2080ti VRAM can be fully be used for rendering only. So, never I touched the 12GB limit of the 2080ti and the 3090 is used above 12GB often - max productivity. If I should need 24GB for rendering than I will simple switch the system to one of the 2080ti. So I can recommend to have one 24GB card at least. Using the 3090 for rendering and system at the same time works quite good.