PCIe x4 into x16, but what about the transfer speeds?

I use a GPU with a PCI E x16 in my PCI E X4 slot What will pcie x4 in x16 slot Comments13 · Explaining PCIe Slots · NVME ADAPTERS pcie slot dimensions 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

pcie 40 in 30 slot PCIe UD Slot X： PCIe x16 slot with 10X strength for graphics card Ultra-Fast Storage：3* slots, including 1* PCIe x4