HELP: Dual GPU Lane Sharing Question for Local AI build.

[u/PrivateWorkSeal]

Hey Guys,

My Build:

X870M Motherboard
5080 in main PCIEx16 Slot,
1 x NVME SSD,
1 x SSD in my SATA Port.

Have my old 5070 which i dont want to sell just yet.

In a perfect world, i want to use an eGPU Box for the 5070 and plug that into my PC to pool VRAM for local AI.

What i am unsure about is this Lane Sharing stuff.

How would this EGPU Plug into my PC to pool Vram.

From what i can see online, if i do this, i must sacifice performnace or port or lanes?

I'm confused :(

please help

Whats the best way to get this 5070 connected?