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How oxide cuts data center power consumption in half

(oxide.computer)
195 points tosh | 6 comments | 21 Nov 24 18:12 UTC | HN request time: 1.492s | source | bottom
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shivak ◴[21 Nov 24 20:31 UTC] No.42208324[source]▶
> > The power shelf distributes DC power up and down the rack via a bus bar. This eliminates the 70 total AC power supplies found in an equivalent legacy server rack within 32 servers, two top-of-rack switches, and one out-of-band switch, each with two AC power supplies

This creates a single point of failure, trading robustness for efficiency. There's nothing wrong with that, but software/ops might have to accommodate by making the opposite tradeoff. In general, the cost savings advertised by cloud infrastructure should be more holistic.

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dralley ◴[21 Nov 24 21:13 UTC] No.42208722[source]▶
>This creates a single point of failure, trading robustness for efficiency. There's nothing wrong with that, but software/ops might have to accommodate by making the opposite tradeoff.

I'll happily take a single high qualify power supply (which may have internal redundancy FWIW) over 70 much more cheaply made power supplies that stress other parts of my datacenter via sheer inefficiency, and also costs more in aggregate. Nobody drives down the highway with 10 spare tires for their SUV.

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1. hn-throw ◴[21 Nov 24 21:25 UTC] No.42208819[source]▶
Let's say your high quality supply's yearly failure rate is 100 times less than the cheap ones

The probability of at least a single failure is 1-(1-r)^70.

This is quite high even w/out considering the higher quality of the one supply.

The probability of all 70 going down is

r^70 which is absurdly low.

Let's say r = 0.05 or one failed supply every 20 in a year.

1-(1-r)^70 = 97% r^70 < 1E-91

The high quality supply has r = 0.0005, in between no failure and all failing. If you code can handle node failure, very many, cheaper supplies appears to be more robust.

(Assuming uncorrelated events. YMMV)

replies(1): >>42208883 #
2. carlhjerpe ◴[21 Nov 24 21:32 UTC] No.42208883[source]▶
Yeah but the failure rate of an analog piece of copper is pretty low, it'll keep being copper unless you do stupid things. You'll have multiple power supplies provide power on the same piece of copper
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3. hn-throw ◴[21 Nov 24 22:16 UTC] No.42209249[source]▶
TL/DR, isnt there a single, shared, DC supply that supplies said piece of copper? Presumably connected to mains?

Or are the running on SOFCs?

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4. mycoliza ◴[21 Nov 24 23:10 UTC] No.42209634{3}[source]▶
The big piece of copper is fed by redundant rectifiers. Each power shelf has six independent rectifiers which are 5+1 redundant if the rack is fully loaded with compute sleds, or 3+3 redundant if the rack is half-populated. Customers who want more redundancy can also have a second power shelf with six more rectifiers.
replies(1): >>42210664 #
5. hn-throw ◴[22 Nov 24 02:35 UTC] No.42210664{4}[source]▶
I'm going to assume this is on 3 phase power, but how is the ripple filtered?
replies(1): >>42211584 #
6. applied_heat ◴[22 Nov 24 06:24 UTC] No.42211584{5}[source]▶
Inductors and capacitors usually