I’m planning on giving an older machine a small upgrade with an SSD, but since that machine does not have an m.2 port, I was thinking about buying the cheapest PCIe adapter I could find. Besides the obvious stuff like ports, PCIe gen and lane count, is there anything I should look out for? Specifically regarding Linux?
As long as the system is new enough that the UEFI supports NVMe, it will be able to boot from it. It doesn’t matter whether or not an adapter is used since the adapter is passive.