RTX 5080 performance on pcie 5.0 x8

So I have a question, I have looked into this online but I haven't found a definite answer.

So I almost finished my build and the only thing that needs to get delivered is the GPU.

CPU is ryzen 7 9800x3d. My motherboard is gigabyte aorus x870 elite wifi7. This motherboard has, if I'm not mistaken 4x m.2 slots, the main one which is PCI 5.0 that's above the GPU slot. And 3 more below the GPU slot of which one is pcie 4.0 and the other 2 are pcie 5.0. The thing about those 2 is that they share the lanes with the GPU.

So if I put an ssd in any of those 2 bottom slots the GPU will go from x16 mode to x8 mode.

So my question is will this affect the performance? If so by how much, at any given resolution.

Because I have enough m.2s to fill all the slots but I won't do it if I'm giving up noticeable performance.

I'd like to hear your thoughts on this.