Why Do Computers Use So Much Energy? • Hacker News Board

Re: Why Do Computers Use So Much Energy?

#91

Post by yread » Thu, Oct 04, 2018, 5:33 PM UTC

flyGuyOnTheSly wrote: post #54

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…

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.

you will need to revise the power once more: when idle modern notebooks use 5-10 W, even under load it's closer to 30 W.

These guys measure idle power consumption for all laptops

https://www.notebookcheck.net/HP-Elite-x2-1013-G3-i5-8350U-S...

Re: Why Do Computers Use So Much Energy?

#92

Post by sixstringtheory » Thu, Oct 04, 2018, 5:34 PM UTC

simias wrote: post #45

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…

>So society's computer uses 5 percent and our own, evolved over millions of years, uses up to 20. This comparison doesn't make a lot of sense to me. It's not even comparing apples to oranges, it's comparing apples to the concept of taste. Furthermore these percentages don't really tell you much regarding efficiency, I'm sure there are less developed societies where computers count for less than 5% of all energy consu…

I second this, in order for it to be a fair comparison we have to level the playing field, by converting the total available calories (for humans) and electricity (for computers) into some common unit that represents the total capacity available to the US (or world). Another commenter brought up Joules which I think would work, I just can’t fully wrap my mind around what all will go into the calculation, like food growing and transport energy requirements, vs power plant emissions, maintenance, coal/oil transport.

Re: Why Do Computers Use So Much Energy?

#93

Post by [deleted] » Thu, Oct 04, 2018, 5:37 PM UTC

dwighttk wrote: post #56

> (We now understand that the second law does not say that the entropy of a closed system cannot increase, only that its expected entropy cannot increase.) they mean decrease, right?

[deleted]

Re: Why Do Computers Use So Much Energy?

#94

Post by agumonkey » Thu, Oct 04, 2018, 5:43 PM UTC

amelius wrote: post #24

> Why Do Computers Use So Much Energy? Ads.

Marketing, industry structure

1: People will buy what's new and shiney.

2: companies produces what can integrate into what sells

3: loop

Re: Why Do Computers Use So Much Energy?

#95

Post by CogitoCogito » Thu, Oct 04, 2018, 5:45 PM UTC

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…

Others have commented why your comparison doesn't really make sense, but you should respect the fact that the human brain is actually incredibly efficient if anything.

https://www.scientificamerican.com/article/thinking-hard-cal...

> So a typical adult human brain runs on around 12 watts—a fifth of the power required by a standard 60 watt lightbulb. Compared with most other organs, the brain is greedy; pitted against man-made electronics, it is astoundingly efficient. IBM's Watson, the supercomputer that defeated Jeopardy! champions, depends on ninety IBM Power 750 servers, each of which requires around one thousand watts.

Re: Why Do Computers Use So Much Energy?

#96

Post by bschwindHN » Thu, Oct 04, 2018, 6:07 PM UTC

zwieback wrote: post #41

amelius wrote: post #24

> Why Do Computers Use So Much Energy? Ads.

Also, wide character sets. ASCII is all anyone ever needed.

Kind of shocked to be reading this... have you ever made software for non-English speaking users? ASCII is not enough.

Re: Why Do Computers Use So Much Energy?

#97

Post by oh_sigh » Thu, Oct 04, 2018, 6:10 PM UTC

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…

You're comparing two different energy sources - Computers use 5% of the energy we produce, whereas human computers use 10-20% of the food-energy we produce. Computers certainly use more energy than all the human brains in the world.

Re: Why Do Computers Use So Much Energy?

#98

Post by ashelmire » Thu, Oct 04, 2018, 6:23 PM UTC

aurelwu wrote: post #51

ashelmire wrote: post #23

Earlier quoted context omitted.

> no good reason If it takes a developer hours to build something that would otherwise take days, that's a very good reason. Processing power and energy are a tiny fraction of the cost of dev time. For things where scale matters, companies switch to faster languages with more optimization. This is irrelevant for what, 95% of businesses? Granted, probably half of devs are working for big tech where it does matter, but…

>energy [is] a tiny fraction of the cost of dev time I think that is in a lot of cases not true, just that the developer (and his company) is not paying the bill but the buyer/user. While individually this might not be a lot, therefore the individual will not complain about it either, for applications with lot of users it will add up a lot. Let's say you have a application or a device with 1 Million Concurrent users,…

Let's be clear about this: high level languages like python and ruby in production use are doing server side web operations, most of which aren't even very intensive - the assertion that this is being offloaded to the user is false. Anything that a low level language would replace is server side. A Java web app still needs to serve the same javascript that a Ruby or Python app does.

Javascript is used client side, and again, it's quite fast, with performance comparable to Java and C++ in most use cases. And a web app is basically never going to reach the cpu/gpu levels that even the lightest game coded in C++ will reach, with rare exceptions.

Re: Why Do Computers Use So Much Energy?

#99

Post by close04 » Thu, Oct 04, 2018, 6:29 PM UTC

noir_lord wrote: post #74

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…

Indeed. I have a Thinkpad that has an i7-7700HQ, that's a 35W TDP beast and even under very heavy load I still get 90 minutes out of a 72 watt-hour battery and it gets pretty warm (and the TP has excellent cooling), 200W would melt your legs.

I guess that's what active cooling is for. So your legs don't have to take the brunt of it. Anyway, a laptop's power consumption isn't concentrated in one chip. So combining the wider area that dissipates heat with the fact that hot spots are actively cooled means a laptop can easily go over the above mentioned 60W for prolonged periods.

And power consumption tends to add up from sources that are otherwise not very power hungry themselves (compared to a CPU or GPU). A few W with the LCD, a few with the SSD/HDD, etc.

Re: Why Do Computers Use So Much Energy?

#100

Post by oconnor663 » Thu, Oct 04, 2018, 6:47 PM UTC

dexen wrote: post #36

There's also the question of how little energy is enough to perform computations, and I've enjoyed greatly a video on the subject by PBS Space Time: "Reversing Entropy with Maxwell's Demon | Space Time" https://www.youtube.com/watch?v=KR23aMjIHIY Turns out even in case of an "ideal Maxwell'S Demon", the memory operation required to handling pass/stop necessitates certain energy use.

The response to comments at the end is amazing. Subscribed.