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A comment on 220,000 cores and counting: largest ever public cloud job. Parent comment

Re:220,000 cores and counting: largest ever public cloud job by pjc50 on Thursday April 20, 2017 @03:00PM (#14159730)
Let's say you're using 2x 10 core CPUs per 1U PC, in a 42U rack. That's 840 cores per rack, 262 racks. You won't fit that in a house, you need a moderately large datacenter.

At 100W per CPU that's 22kW, which feels low; about a tenth of a Tesla and a fraction of a plane. That doesn't account for the cooling you'll need!

(You can probably do a lot better, but that's my piano tuners estimate)

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Re:220,000 cores and counting: largest ever public cloud job by TheSpiceIsLife on Thursday April 20, 2017 @03:42PM (#14160118)
22kW of CPU heat would need 22kW of cooling. Refrigerated air conditioning is has about 1:3 thermal efficiency, so your cooling system will require ~7.5kW electricity to generate 22kW cooling capacity.

That makes about 30kW. At $0.15 / kWh we're talking about $4.5 per hour for the electricity.

Other costs dwarf the energy costs.

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Re:220,000 cores and counting: largest ever public cloud job by JonyEpsilon on Thursday April 20, 2017 @08:19PM (#14162063)
If it were 10 cores/CPU then 220,000 cores is 22,000 CPUs. At 100W per CPU that's 2,200,000W = 2.2MW. So more like a train than a Tesla!
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Re:220,000 cores and counting: largest ever public cloud job by lightcatcher on Friday April 21, 2017 @02:25AM (#14163487)
Yes, and based on the $0.15/kWh comment, about $450/hour of electricity.

This is more in line with what I would have guessed for 220k cores.

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Re:220,000 cores and counting: largest ever public cloud job by zaroth on Friday April 21, 2017 @01:14AM (#14163248)
So ~$300/hour in electricity.
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Re:220,000 cores and counting: largest ever public cloud job by mikeash on Thursday April 20, 2017 @04:21PM (#14160478)
Note that 22kW is right about what a Tesla will consume cruising at highway speeds. So you could label that as "an efficient cruising car."
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Re:220,000 cores and counting: largest ever public cloud job by brianwawok on Thursday April 20, 2017 @03:36PM (#14160052)
I would be shocked if Google wasn't getting 2x 32 core CPUs per 1U at a minimum, which brings down your rack count a bit.
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Re:220,000 cores and counting: largest ever public cloud job by minxomat on Thursday April 20, 2017 @08:19PM (#14162068)
Even if those were ARM cores (currently 192 cores/U @ 1.8 GHz), it would still take about 30 racks. ARM sucks at single-core performance, but it handles parallel workloads very well.
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