Verilux® NVME Adapter PCIe x16 with Gel Pad, -

RTX 3080: x4, x8, or x16 PCIe Slots - What Changes the pcie x4 in x16 slot Install a PCI Express x16 card into a PCI Express x4 slot, in a 1U chassis The PEX4TO16R PCI Express x4 to x16 Slot Extension Adapter lets you install PCI pcie 4 nvme in pcie 3 slot PCIe slots come in different sizes, with the most common being PCIe x1, PCIe x4, PCIe x8, and PCIe x16, which indicate the number of lanes

pcie slot pinout So your adaptec x4 card will run at x4 in a x16 slot It's a good sign the x1 card works, but still isnt proof the x4 will work Ideally for