I am considering buying a new motherboard for a home server which I can upgrade over time, and the ASRock Rack ROMED8-2T looks pretty future-proof. I want to put a second-hand 7251 in it to start with.
The main selling point of the board is its PCIE 4.0 slots, but the 7251 only supports PCIE 3.0. The manual claims I can use this CPU, so what happens to the slots? Do they just gracefully run at PCIE 3.0 speeds? Similarly, what is likely to happen with the M.2 slots which share the PCIE lanes with the second slot?