Need help for multi GPU configuration

[Imagirium]

Hello,

I plan to build a new computer that will be, amongst other things, used for rendering purpose.

My question is about the PCIeLanes. I already read older post but i'm not quite sure about the answers provided.

As i want 3 GPU (and may be a 4th later, but 3 will be nice) i'm not sure what CPU to choose because of pcieLanes.

If i go for mainstream like Ryzen 3900x i will have only 24 lanes. With a PLX motherboard like this Asus ( https://www.asus.com/Motherboards/Pro-WS-X570-ACE/) i will have 8x8x8. But won't be able to put 4 graphic cards on x8.

The question is : what about drop of power with x4 instead of x8 (i m not taking care about the loading time of the scene). I read that x8 vs x16 is quite the same., but could not find some test about x4 vs x8. To make matters worse someone told me that even x1 won't make any difference while rendering....

[Imagirium]

I changed my mind and i will go for a 3960x as there is no other way to do it

Could some dude with 4 GPU workstation provide advices about the case ? All GPU will be with blower.

[jimho]

regard to PCIE lanes for rendering pupose x8 is basic,
x1 is for mining machine, they are different.

[Lewis]

I changed my mind and i will go for a 3960x as there is no other way to do it

Could some dude with 4 GPU workstation provide advices about the case ? All GPU will be with blower.

you need case with at least 8 exit brackets (preferably 9) and it has to be supertower/big tower with great front intake fans/airflow, otherwise your GPUs will overheat and throttle to very low speeds = render slower.

I use Thermaltake W200 (double size for 2 PCs) but you can go with Thermaltake W100 for single width/PC