Used 10GbE ethernet components are cheap on ebay. I built a 10GbE 'switch' by buying 2 4 port SPI+ PCIE cards off of Ebay and then joining them together with a

Used 10GbE ethernet components are cheap on ebay. I built a 10GbE 'switch' by buying 2 4 port SPI+ PCIE cards off of Ebay and then joining them together with a conventional Linux Br0 bridge on a old Intel gaming machine. Had no problem keeping up with line speed. I didn't test wireguard with it, but it should work pretty effectively for testing what speed it can get up to.