> You'll need: An always-on Linux device on the same network as your server, e.g. a Raspberry Pi
> First, a bit about my hardware, as this solution is somewhat hardware-dependent: HP ProDesk 600 G3 SFF
I seriously doubt any of this can be gotten to work on a Pi in a way that actually reduces power usage in any notable way. Hell the Pi 4 uses almost full idle current when completely powered off unless you turn off just about everything that would make it possible to wake up again without a full power cycle. And even then the draw remains significant.
Many people who would do this sort of thing likely already have an always-on pi (pi-hole, dns, ssh jump box, etc). And even at full bore, pi 4 is about 6.5W, so 90% savings over the HP.
> First, a bit about my hardware, as this solution is somewhat hardware-dependent: HP ProDesk 600 G3 SFF
I seriously doubt any of this can be gotten to work on a Pi in a way that actually reduces power usage in any notable way. Hell the Pi 4 uses almost full idle current when completely powered off unless you turn off just about everything that would make it possible to wake up again without a full power cycle. And even then the draw remains significant.