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Why Do Computers Use So Much Energy?

blogs.scientificamerican.com

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Re: Why Do Computers Use So Much Energy?

#151

Post by dredmorbius »

phyzome wrote: post #138
flyGuyOnTheSly wrote: post #54

Earlier quoted context omitted.

My thoughts exactly. When reading the title I thought "They do?" My laptop consumes the equivalent of approximately a single 60w incandescent lightbulb that used to be required just to write on a pad of paper in the dark. It's capable of quite a bit more than that, however. EDIT: Updated power specifications to exact amounts.

I was going to say that you could write just fine by candlelight instead, but it turns out a candle uses about as much energy as that light bulb (based on random internet spot-checks).

The increase in energy-to-services efficiency of lighting has been stupendous. If you go all the way back to brands or torches (the burning sort), candles, oil lamps, gas mantles, incandescent, fluorescent, and now LED.

I have to keep reminding older concerned family members that a light might consume a dollar's worth of electricity per year, or that the bright overhead floods actually consume half the power of the 'low-energy' under-cabinet system (incandescent).

Re: Why Do Computers Use So Much Energy?

#152

Post by sokoloff »

8bitsrule wrote: post #141
lucideer wrote: post #12

> Precise estimates vary, but currently about 5 percent of all energy consumption in the U.S. goes just to running computers 30% goes on transport. > the human brain is a computer. This particular computer uses some 10–20 percent of all the calories that a human consumes So society's computer uses 5 percent and our own, evolved over millions of years, uses up to 20. I'm not saying computers can't or shouldn't be made…

For anyone heating their home/office in the winter, the energy consumed by their computer effectively has zero cost. The computing done is value added to energy-use that would otherwise dissipate through the walls and ceiling. Those of us in northern latitudes should be lucky enough to have a couple of servers in the closet helping to pay for heating.

Only if you’re heating your house with electric resistance heat.

Heating with natural gas or heat pump is more efficient (in terms of BTU per dollar) than using the waste heat from computing (which is resistance).

Re: Why Do Computers Use So Much Energy?

#153

Post by rplst8 »

ced wrote: post #144
8bitsrule wrote: post #141

Earlier quoted context omitted.

For anyone heating their home/office in the winter, the energy consumed by their computer effectively has zero cost. The computing done is value added to energy-use that would otherwise dissipate through the walls and ceiling. Those of us in northern latitudes should be lucky enough to have a couple of servers in the closet helping to pay for heating.

Yeah, but who moves their computers outside of the closet in the summer? Then we have a larger AC bill to cover, and that's less efficient than heating.

A/C moves heat at some energy cost. It's not 1:1 with heating.

Re: Why Do Computers Use So Much Energy?

#154

Post by why_only_15 »

platz wrote: post #86

because CPUs are the least efficient computing device, precisely because they are so general. The future of hardware will be reprogrammable circuits that specialize to repeatable tasks ICFP 2018 Keynote Address: The Role of Functional Programming and DSLs in Hardware https://www.youtube.com/watch?v=VqYkcGRr8x0

But why? Most of e.g. a website is the software, not the hardware. Making the hardware cheaper but the software more expensive (e.g. with a DSL) is counterintuitive.

Re: Why Do Computers Use So Much Energy?

#159

Post by pessimizer »

mcbits wrote: post #112
peeters wrote: post #105

Earlier quoted context omitted.

One is saying how much computers use of a global resource pool, the other is how much brains use of their host body. They're completely different things so it doesn't make sense to compare those two percentages. If you wanted to compare them, cite the percent that the CPU uses of its PSU, or cite the percent that human brains use of global energy consumption. Otherwise they're completely different things that have no…

One is viewing society as a "body" with computers being its "brain". The other is viewing the human body as a "body" with its brain being its "brain". The comparison is of the energy used by each "brain" relative to the total energy used by its "body". The comparison is valid if you accept the analogy, although I think you could easily dispute the analogy. E.g. you could just as easily view the network of humans in a…

> you could just as easily view the network of humans in a society as its "brain"

You could far more easily view the brains of humans in a society as its "brains."

Re: Why Do Computers Use So Much Energy?

#160

Post by stuaxo »

derefr wrote: post #118
orev wrote: post #66

Earlier quoted context omitted.

If your laptop consumed that much power it would be too hot to use on your lap and also would probably damage whatever surface you put it on. Just because a power supply has a max rating of X Watts doesn’t mean it’s always using that much. Even then, 200w for a laptop is an enormous amount. Maybe you meant LED bulbs that emit the equivalent light of a 100w bulb? That would be much closer to standard laptop power cons…

> If your laptop consumed that much power it would be too hot to use on your lap A lot of laptops do actually get too hot (and are too heavy) to effectively be used on laps. Some even require two concurrent power connections from two separate power bricks in order to charge!

Pretty much all laptops have a sticker underneath that tells you not to use them on a lap.

My old dusty i7 laptop did get much much too hot though.

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