20KW? Wow. That's a lot of power. Is that figure per hour?

If you run it for an hour, yes.

I asked because that's the average power consumption of an average household in the US per day. So, if that figure is per hour, that's equivalent to one household worth of power consumption per hour...which is a lot.

Others clarified the kW versus kWh, but to re-visit the comparison to a household:

One household uses about 30 kWh per day.

20 kW * 24 = 480 kWh per day for the server.

So you're looking at one server (if parent's 20kW number is accurate - I see other sources saying even 25kW) consuming 16 households worth of energy.

For comparison, a hair dryer uses around 1.5 kW of energy, which is just below the rating for most US home electrical circuits. This is something like 13 hair dryers going on full blast.

Which honestly doesn't sound that bad given how many users one server is able to serve.

At least with GPT-5.3-Codex-Spark, I gather most of the AI inference isn't rendering cat videos but mostly useful work.. so I don't feel tooo bad about 16 households worth of energy.

To be fair, this is 16 households of electrical energy. The average household uses about as much electrical energy as it uses energy in form of natural gas (or butane or fuel oil, depending on what they use). And then roughly as much gasoline as they use electricity. So really more like 5 households of energy. And that's just your direct energy use, not accounting for all the products including food consumed in the average household.

Consumption of a house per day is measured in kiloWatt-hours (an amount of power like litres of water), not kiloWatts (a flow of power like 1 litre per second of water).

1 Watt = 1 Joule per second.

Thanks!

I think you are confusing KW (kilowatt) with KWH (kilowatt hour).

A KW is a unit of power while a KWH is a unit of energy. Power is a measure of energy transferred in an amount of time, which is why you rate an electronic device’s energy usage using power; it consumes energy over time.

In terms of paying for electricity, you care about the total energy consumed, which is why your electric bill is denominated in KWH, which is the amount of energy used if you use one kilowatt of power for one hour.

You're right, I absolutely was mixing them both. Thanks for clarifying!

Acktshually "kW" and "kWh" to be precise

Ah yes, like those EV chargers that are rated at X kWh/hour.

You would hope that an EV reporting x kWh/hour considers the charge curve when charging for an hour. Then it makes sense to report that instead of the peak kW rating. But reality is that they just report the peak kW rating as the "kWh/hour" :-(

It’s 20kW for as long as you can afford the power bill

What do you mean by "per hour"?

Watt is a measure of power, that is a rate: Joule/second, [energy/time]

> The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3.[1][2][3] It is used to quantify the rate of energy transfer.

https://en.wikipedia.org/wiki/Watt

20 kWh per hour

That’s wild. That’s like running 15 indoor heaters at the same time.

A first-gen Oxide Computer rack puts out max 15 kW of power, and they manage to do that with air cooling. The liquid-cooled AI racks being used today for training and inference workloads almost certainly have far higher power output than that.

(Bringing liquid cooling to the racks likely has to be one of the biggest challenges with this whole new HPC/AI datacenter infrastructure, so the fact that an aircooled rack can just sit in mostly any ordinary facility is a non-trivial advantage.)

Well for some. Google has been using liquid cooling to racks for decades.

> Bringing liquid cooling to the racks likely has to be one of the biggest challenges with this whole new HPC/AI

Are you sure about that? HPC has had full rack liquid cooling for a long time now.

The primary challenge with the current generation is the unusual increase of power density in racks. This necessitates upgrades in capacity, notably getting 10-20 kWh of heat away from few Us is generally though but if done can increase density.

HPC is also not a normal data center but also usually doesn't have the scale of hyperscaler AI data centers either.

> The liquid-cooled AI racks being used today for training and inference workloads almost certainly have far higher power output than that.

75kW is a sane "default baseline" and you can find plenty of deployments at 130kW.

There's talk of pushing to 240kW and beyond...