SSD NVMe in a Gen2x4 slot, Bad Idea?

[HyeVltg3]

My second M.2 slot is rated a "M.2 Socket (PCIe Gen2 x4)"

Will putting a M.2 NVMe SDD in there be a bad idea? or will I just be losing out on speeds.
Really wondering if I will have any compatibility issues.
Only using this for a Data Drive, already using my other M.2 slot as Boot.

Board: ASRock Fatal1ty X370 Professional Gaming
OS: Win10 x64
GPU: RX Vega64

Also curious, will I have any lane issues on X370 and 1700X ??

 

[SkyNetRising]

Will putting a M.2 NVMe SDD in there be a bad idea?

It's not a bad idea.
Just you can't use second M.2 slot together with PCIE5 slot (one of them gets disabled, when other is used).

 

[HyeVltg3]

Will putting a M.2 NVMe SDD in there be a bad idea?

It's not a bad idea.
Just you can't use second M.2 slot together with PCIE5 slot (one of them gets disabled, when other is used).

Took me a bit to realize that there was another PCIE slot below the M.2, its all black barely noticed it (staring from my side window)
I can definitely live without it, thanks a lot man, was really scratching my head about buying another (bigger, now that the prices have come down) M.2 drive but it was a toss-up between a "normal" M.2 drive statings speeds of ~500MB/s or a NVMe drive that usually stated 2000MB/s+.
PCIE Gen2x4 on my mobo can do 20Gb/s = theoretically 2560MB/s, so I think I'm good with getting a NVMe drive, I wont be losing out too much, but alls I didnt know were if my setup could handle it especially when Lanes came into the picture.