Using LSI 2308 in PCIE x1 mode, what will I lose?

Also there is Double and Triple PCIe cards Those cards fill corresponding PCIe slot count on equipment interface panel

PCIe x1 to PCIe x16 Slot Extension adapter Features & details Features Item Height, ‎ Inches Item Width, ‎ Inches Product Dimensions, ‎ x

pcie 20 x1 slot As per Wikipedia and other sites, the dimensions of the half-length PCIe card are mm × mm But as per the specification: enter

pcie nvme slot PCIe Gen3 x4 PCIe slot to SFF-8644 Passive Adapter Quick View Part #:, PCI-AD The adapter comes with an adjustable 15mm tool-less fixture and full-height