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Comment by 9dev | Hacker News Reader

I'm still curious what you'd need a rack consuming 1kw for… in your garage. From the photo, it looks like lots of storage(?).

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My hard drives alone pull 200W idle and I don’t have that many. Cooling fans (in servers) pull 150W total most of the time but can be up to 300W. Each 10GbE NIC pulls ~40W. PoE switch gives ~30W to each of my APs, and uses ~80W itself, so there’s another 300W. All of my RAM pulls about 250W (admittedly there’s nearly 2TB of it in the rack, but still). Start adding up CPUs idle/average/max power and the numbers get way bigger.

If all he’s pulling is 1kW I’m jealous.

If I had more than 100 watts in idle hard drives, I'd start aggressively figuring out how to let them spin down. Maybe his drives are actually doing something 24 hours a day? But probably not.

Networking gear taking that much when it's not busy is really unfortunate. Did IEEE slack on adding effective sleep/downclocking features?

It sounds like the 10GbE is not fiber. With fiber, it would take around 5W only, depending on your needs. It's a bit harder to use, but fiber is really the better option if you want a serious homelab.

> Cooling fans (in servers) pull 150W total most of the time but can be up to 300W.

Oxide Computer found that going from tiny 20mm fans to 80mm dropped their chassis power usage bigly: they found a rack full of 1U servers had 25% of its power going to the fans (efficiency is to the cube of the radius).

* https://www.youtube.com/watch?v=hTJYY_Y1H9Q

My mental model is that such a choice is why a data center is deafening: all those tiny fans spinning at hella rpm

40W for a 10GbE NIC sounds crazy, my internet router has a dual 10 GbE Intel NIC with one 10GBaseT SFP+ and one 10G DAC and the whole router only draws 24 W (Lenovo ThinkCentre Tiny)

My whole “rack” draws about 120W total with: aforementioned router, Synology NAS with 4 drives, 2x10G+4x2.5G PoE switch powering a Ubiquiti AP, 16-port 1G switch, and a PowerBook 540c running AppleTalk routing

I'm running 100G CWDM4s in my homelab, and those only take about 4w each for the optics, so I suspect with the PCIe card it is less than 10w.

Late response I know, but copper 10GbE nics pull lots of power, especially the old X540 ones.

I'm curious, are you getting this with a kill-a-watt (or equivalent), or are you adding up wattage by specifications alone?

(I do have an epyc with a bunch of memory and storage, but never bothered doing the math since my UPS claims to be able to run with the average load for 30+mins)

Measured at the UPS, which has 1W resolution. Confirmed its accuracy with an amp clamp on the circuit when running the UPS in pass-through mode. Efficiency is even worse most of the time since it’s a double-conversion (online) UPS that I normally run in full conversion mode - something like 80-85% efficiency overall, but because I fall back to generator power relatively frequently I just leave it there for convenience (in case I’m not home to switch it when the generator’s turned on).

1kW sounds pretty good to me!

My homelab is between 4 and 8 kW continuously, depending on what I have running. Cooling that homelab is another 400-1000 watts depending on outside air temp.

Yeah, I wondered the same.

He mentioned that he refuses downsizing for ideological reasons, and I totally get that, but there's a certain amount of rightsizing that doesn't hurt in practical operation, and still let's you keep what feels like an awesome, big, complex model train setup in your garage.

Not all rust has to spin, almost no ports have to be 10GE, and a lot can be virtualized. Consumer CPUs have much lower idle than old xeons, and having less DIMMs with the same capacity also seems to pay off.

I'd be surprised if he couldn't cut that energy usage to 10% with a clear separation between hot and cold storage, and realistic expectations of bandwidth requirements.

But hey, I'm not judging. Solar power is great, and I don't mind waste as long as he can afford it and it makes him happy. Nobody drives the car they actually need either, and that is a much bigger problem.

1kW is less than a toaster, fwiw.

I draw 1-1.5kW for my servers in a spare bedroom. It’s not a lot of spindles/cores, just a few dozen.

1kW continuously is 8760kWh per year. To compare, my house used 6200kWh in total over 2024, including heating.

Your toaster draws 1kW for maybe 5 minutes a day, which is maybe 30kWh per year.

The power in this comparison is not important, it's the total energy consumed (which is what you are billed for in the end).

yes, computers use a lot of energy, and spinning disks in my 40 hard drives use even more.

Not many people run their toaster 24/7/365

It is always surprising to me but small loads that are on 24/7 end up consuming a ton of energy. My 55W idle "homelab" consumes as much energy as my dishwasher, fridge and washing machine combined.

> 1kW is less than a toaster, fwiw.

Odd argument. A cheetah can run up to 110kmh, but that doesn't mean they can cross 110 kilometres in an hour.

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