4x Expansion Board vs Single PCIe x4 NVMe Drive

Which Slot Should You Use? m2 expansion slot One slot for storage Any of the expansion slots can be turned into storage, either by the Framework sold units, or making one yourself m2 slot screw My SSD connected to my board but speedtest gives me 3Gbs If I buy pcie expansion card can it be faster than onboard slot? Onboard m2 slot or

m2 slot 2 slot support NVMe? Does the slot support Intel Optane? XPC cube SH55J2, PCIe x16 , PCI 32-