Combining RTX 3090 with two GTX 1080ti

[chris6885]

Hi guys,

I am trying to find valuable info for this topic, but my technological knowledge is just too small to really understand most of it.
Here is my situation:
I am working in Cinema 4D with Octane as my main engine for mostly animation work. I just bought a new machine with a single 3090.
My old machine has two 1080ti inside and I was thinking if it would be a smart move to keep them and put one (or even both) of them next to the 3090.
Now my stupid brain would tell me "sure, then I will have 46 GB of VRAM" but I know it is not that simple.
So could someone break it down for me if there are any advantages of putting those cards together or if it would be just a waste of money.

If you need more info about the board or CPU:
ASUS PRO WS WRX80E
AMD Ryzen Threadripper PRO 3955WX

Thanks upfront
Christian

[galleon27]

The more GPUs, the better. The scene needs to be loaded on every single GPU, meaning that you are limited by the card with the lowest amount of memory, in your case 11gb. If you need more that 11gb, you will have to exclude both 1080ti's when rendering.
You might also run into some issues with GPU temperatures if they are not blower style and you stack them too close to each other. Maybe someone more knowledgeable might be able to give more details on that.
You also have the option keep the two 1080ti's in your old machine and use it as a slave machine. Render node costs 99€/year or 9.99€/month.