Another downside is powerconsumption at rest. Supermicro board with 2x Xeon use 80watt at minimum. Add a 10Gbit switch and a few more peripherals and you’re looking at an additional $€80/month electricity bill. Year after year, that is $€10.000 in 10years.

Of course that is nothing compared to what you’d pay at Google/Azure/AWS for the AMD machine of this news item :-)

12V only PSUs like OEMs use or ATX12VO in combination with a motherboard without IPMI, similar to the German Fujitsu motherboards, have significant lower power consumption at rest. Somewhere around 8-10Watt without HDD. Much better for home use IHMO.

In the US, electricity rates are typically much cheaper than the EU. My rate is roughly .08 €/kWh, for example, and I don't get any subsidies to convert to solar, so I have no way to make it pay off for myself within 15 years (beyond the time most people expect to stay in a home here), while other states in the US subsidize so heavily or rates for electricity are so high most people have solar panels at least (see: Hawaii with among the highest costs for electricity in the US).

Regardless of electricity cost, all that electricity usage winds up with a lot of heat in a dwelling. To help offset the energy consumption in the future I plan to use a hybrid water heater that can act as a heat pump and dehumidifier and capture the excess heat as a way to reduce energy consumption for hot water.

It’s mostly about casing though - density is important with enterprise stuff, and noise level is almost irrelevant hence small chassis with small, loud, fans.

I’ve got a 3.5” x16 bay gooxi chassis that I’ve put a supermicro mb + xeon in.

Something like this:

https://www.xcase.co.uk/collections/3u-rackmount-cases/produ...

I got this specific nas chassis because it got a fan wall with 3x120mm fans, not because I need bays.

With a few rather cool SSD’s for storage and quiet noctua fans it is barely a whisper.

Also - vertical rack mounting behind a closet door! I can have a massive chassis that basically takes no place at all. Can’t belive I didn’t figure that one out earlier...

Noise isn't the only downside - the power they consume can cost $$$. These things aren't typically the most energy efficient machines.

Would swapping them out for Noctuas be difficult?

Mostly yes because server chassis are very compact and sometimes use proprietary connectors and fans. Still, many people have done that with good results, have a look in YouTube to know which server models are best suited for that kind of customization.

I've not been successful trying this with HPE servers. Most server fans (Foxconn/Delta) run 2.8 amp or higher. Not aware of any "silent" gaming grade fans that use more than 0.38 amps. That's not even considering the CFM.

Why would current be relevant here? Shouldn’t operating voltage be the only thing that matters?

Amps * Volts is power. Power is a proxy (a moderately good one) for air movement (a mix of volume/mass at a specific [back-]pressure).

It’s not likely that a silent 2W fan will move a similar amount of air as the stock 14W fans. The enterprise gear from HPE is pretty well engineered; I’m skeptical that they over-designed the fans by a 7x factor.

Operating voltage tells you “this fan won’t burn up when you plug it in”. It doesn’t tell you “will keep the components cool”.