Seriously. 24/7 adds up faster than most realize!

The idle wattage per module has shrunk from 2.5-3W down to 1-1.2 between DDR3 & DDR5. Assuming a 1.3W difference (so 10.4W for 8760 hours), a DDR3 machine with 8 sticks would increase your yearly power consumption by almost 1% (assuming avg 10,500kWh/yr household)

That's only a couple dollars in most cases but the gap is only larger in every other instance. When I upgraded from Zen 2 to Zen 3 it was able to complete the same workload just as fast with half as many cores while pulling over 100W less. Sustained 100% utilization barely even heats a room effectively anymore!

The one thing to be careful with Zen 2 onwards is that if your server is going to be idling most of the time then the majority of your power usage comes from the IO die. Quite a few times you'd be better off with the "less efficient" Intel chips because they save 10-20 Watts when doing nothing.

Wake on LAN?