The Synology DS1821+ reserves a PCIe 3.0 x8 slot for 10GbE upgrades

The DS1821+ ships with four Gigabit Ethernet ports only — there’s no 10GbE onboard. But like the DS1621+, it hides a PCIe Gen3 x8 slot that can take a 10GbE network card. For an eight-bay NAS, that’s almost essential: with six or eight drives spinning, Gigabit becomes the bottleneck fast.