I don't know how that Synology DS423+ could consume 50W idle.
It seems veeery strange to me. I mean, my E5-2620 V2 on a 10/15 years old Supermicro motherboard with 16GB of RAM, 4 idle SATA 3,5" hard drives and 2 SSD is consuming 55W!
Something doesn't sound right to me.