It’s nothing special. Server is custom, built in an Inter-Tech 4U case with 8 hotswap bays, using an x99 motherboard.
Networking is Ubiquiti, with a PoE-capable switch to provide power to access points and cameras.
A big difference was made by making ProxMox use a power plan that lets CPU go idle or clock down, which I think was good for like 20-25 watts. My Windows 10 VM is less responsive in RDP, but otherwise doesn’t seem affected, and the Linux-based VMs don’t seem to care.
Well, a DDR4 RAM stick would use 2-4W, so 32 sticks is 64-128W alone. 4 CPUs don't help either. :)
Given it's only 512MB, it could be achieved with just 8 64GB modules, which would save a bit of power, but that's also a lot of money to put into what is after all somewhat obsolete hardware. (And I say that running a v4 Xeon as well :P)