PCI Express

The article states the Samsung 990 is a PCIe 4.0 x4 drive, not PCIe 5.0, so it will be limited to PCIe 4.0 performance. Answered

Installing the Rocket 1604L in a PCIe x16 slot furthest from the CPU does not add latency for small random I/O workloads compared with a motherboard-integrated M.2 connection because the card's Active Retimer Architecture restores the electrical signal and provides a "Zero-Distance" data path, ensuring deterministic latency and bit-perfect reliability equivalent to a direct motherboard connection. The retimer eliminates signal degradation and the added latency that standard cards can suffer when installed farther from the CPU. Answered

Yes, all M.2 NVMe 2280 sockets have the same physical connectors, and you can put a PCIe Gen 5.0 SSD in a Gen 4.0 or 3.0 socket, or vice versa. However, your SSD’s peak speeds will be limited by the interface you use. PCIe Gen 4.0 x4 tops out at around 7,400MB/s in real-world use, for example, and PCIe Gen 3.0 x4 is half that again, and your SSD can only go as fast as its interface. As such, you could wipe a good deal of potential performance off your drive by putting a Gen 5.0 SSD in a Gen 4.0 slot, but not the other way round.

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