Rome is nominally 225W/socket on the very high end of the price range; a 4P config puts you at 900W for the CPUs. Depending on other peripherals you might be at 1200-1500W total but I don't think you necessarily go much past that unless you're loading it up with power hungry graphics cards or something. You'd definitely want an efficient power supply!
You're right to express some concern -- practical residential limit for continuous load on a perfect incarnation of the typical residential circuit is something like 1440W total (80% of nominal 15A breaker on 120VAC).
Maybe more realistic mid-range products are 155-180W/socket, and that drops the CPU draw down to 620-720W.
Wait, in the US you use 15A at 120v? Here in Europe (Spain at least) the typical is 16A at 240v. 1500W isn't that much of a problem. Oven breakers are even 20 or 32A.
> Wait, in the US you use 15A at 120v? Here in Europe (Spain at least) the typical is 16A at 240v.
Yep! The typical US residential circuit is only 120v, 15A breaker (so 12A at 80% load). (And that may be only 110-120v.) 20A circuits are also fairly common, but it's not the most common; the majority of wall outlets in a US house will be 15A.
In this chart, https://en.wikipedia.org/wiki/NEMA_connector#/media/File:NEM... , the commonly used US residential sockets are NEMA 5-15 (labelled "Typical Outlet," for 15A breaker circuits), NEMA 5-20 (for, duh, 20A breaker circuits), and NEMA 1-15 ("Old Outlet," in older buildings).
> 1500W isn't that much of a problem. Oven breakers are even 20 or 32A.
We do have higher amperage circuits for appliances like ovens and clothes driers, but they're usually dedicated circuits and have different socket shapes. You can see the labels "Clothes Dryer" and "Electric Oven" in the chart linked above :-).
Computer PSUs are generally more efficient at european electical standards. I read many a thread two years ago about cryptominers in America wiring our heavy appliance 220v lines into their racks to approach the efficiency that PSUs can reach at higher volts.
And of course some datacenters just wire DC to the whole schebang instead of having an individual, well two redundant, PSUs per server.
