Asrock amd x570 creator mega info

Hi there,

I’m still a bit confused about these lanes.

So with the Asrock x570 creator and a 3950x, after you use the gpu slot at 16x and only the top m.2 slot, you will be out of lanes ?
I want to add a second m.2 PCIe 4.0 drive at full speed, not disabling any sata ports.

If I understand correctly, if I used the 2nd m.2 slot on the motherboard, it will disable the last 4 SATA ports only ?
I read somewhere Asrock Creator did it differently and would disable the third PCIe slot on the motherboard instead.
In any case, will a gigabyte PCIe 4.0 m.2 ssd run at full speed in this second slot ?

Or is it better to add a “PCIe 4.0 adapter m2-card” and run the gpu slot at 8x lanes ?

Currently I have a 980GTX that doesn’t saturate 8x PCIe 3.0, the 2080ti however, does…
But since this board supports PCIe 4.0 and thus double the bandwidth, if I run a 2080ti on this board in 8x lanes, will it be running at PCIe 3.0 or PCIe 4.0 ?
Or do you need the GPU card to be PCIe 4.0 as well ?

Thank you in advance !