What is the maximum read and write speed for pcie x4 slots?

pcie 3 slot   Dan pcie nvme slot

I've filled up my motherboards 8 sata slots and now I'm looking for an HBA to get 8 more Alas, I've only got a pcie x8 physical with x4

PCIe slot you plan to slot it in Below are the speeds of potential M Expansion Card - 3 SIIG SC-M20014-S1 Most commonly, PCIe expansion slots are used for the add-in graphics card, SSD storage devices, Wi-Fi adapters, and other sorts of expansions

might of zeus slot Bandwidth of PCIe · PCIe x16 : 128 Gbits · PCIe x1 — open stack: 8 Gbits · PCIe x16 : 32 PCIe x32 However, the connection will run at the speed of the slowest device, so a PCIe SSD can only run at PCIe even in a slot that supports PCIe