Question Very confused about how many PCIe lanes I have and how to use them

[Mojavehigh]

I am building a system around an AMD Ryzen 7 2700x, which I understand has 20 lanes of PCIe 3. I would like to put that in an X470 motherboard, which I believe has PCIe 2 lanes (although I am not sure how many) and 1 or 2 M.2 slots.

If I plug a GPU into one of the PCIe x16 slots, that takes away 16 lanes from the CPU with 4 remaining.
If I plug in a NVMe M.2 SSD, does that use the chipset lanes?
What if I include a second NVMe M.2 SSD? I assume that also uses the chipset lanes.

Sorry, I am very new to all of this and this is my first build.
Basically, what I want is a 2700X in an X470 with a GPU and an NVMe M.2, but I would like the possibility of adding a second NVMe M.2 in the future. Will that all work?

Thanks!

 

[tennis2]

The 8 PCIe 2.0 lanes are not used for the GPU. That's 20-16 = 4x2 = 8.

 

[mdd1963]

The X470 and Ryzen have lanes to spare, you can certainly get full a full 16 lanes for a GPU, and a full 4 lanes for each M.2 /NVME slot for MBs that support two NVME M.2 slots...; even a Z390 chipset can do this, although at the expense of a few SATA ports quite often.

 

[TJ Hooker]

1st NVMe SSD would use CPU lanes, 2nd would use chipset lanes.

Yes, you could use a GPU and two NVMe SSDs, and they would all have their full supported number of lanes (x16, x4, and x4), but the lanes for the 2nd SSD would only be PCIe 2.0.