AHCI PCIe SSD question

[pmc25]

Spec states PCIe 3.0 x4 spec on all of them, but I assume they will all work, and to their full speed, in a PCIe 2.0 x8 or x16 slot? I want to get one for the AMD G34 rig I'm building, and it lacks both SATA6Gbps and PCIe 3.0 ... so an AHCI PCIe drive seems like the natural choice. I know NVME won't work as it's not supported in the BIOS .. AHCI ought to, but I need to know if they require PCIe 3.0

Otherwise I assume I need to get an M2 PCIe 2.0 SSD, and a PCIe -> M2 adapter?

 

[Trying]

I am no expert, but I think you may be looking at this from the wrong angle.

These drives work at x4 max.. ie. utilise 4 lanes of the PCIe slot.
So the bandwidth capability of each lane of the PCIe slot is what will affect the drives speed to a max of x4.
I could be wrong, but that is how I have interpreted their current ability.