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Koomey's law
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- jostmey 10y agoHas this law still held over the past few years ever since Intel has been unable to transition to 10nm?
- gwern 10y agoA version, perhaps, at least for GPUs - you can tell because we've gotten much faster new chips like the Pascal GPUs, but no one has needed to run new power lines to their rooms in order to use them.
- googsh0tz 10y agoThat's only because it's cheaper to build a whole new facility
- gwern 10y agoUh... people aren't 'building whole new facilities' for their gaming desktops. The new GPUs also have the same rated power consumption.
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- tdb7893 10y agoThis is my guess. I think that soon we will start to hit limits for single threaded performance so eventually we will just keep adding support for more threads to increase performance
- magila 10y agoPascal was indeed a big jump in efficiency, but that by itself doesn't really reflect the longer term trend. Prior to Pascal efficiency had stalled for a couple of years as GPUs were stuck on a 28nm process for much longer than previous node sizes. This pattern is likely to continue as advancements in fabrication continue to slow down and architectural gains become smaller.
- amelius 10y agoUnfortunately, due to bloating, we perform more than double the number of computations.
- seanp2k2 10y agoI look at things like "how long does it take to enter 100 values into a spreadsheet". Back in DOS days, it was as fast as you could type. With Google Sheets, there is some lag sometimes. Many orders of magnitude more computing power, but how have we improved the actual experience and productivity?
- SilasX 10y agoYes! It infuriates me how entering text into a field in a browser can now have lag and hiccups.
- AnimalMuppet 10y agoBut that's network lag, not computation inefficiency. Compare either a spreadsheet program running on a mainframe back around 1990 to Google Sheets, or else compare a DOS spreadsheet to a spreadsheet running locally on Windows today.
- petters 10y agoWould still be an interesting comparison, with some Electron apps using 16% CPU to blink the cursor.
- SilasX 10y agoThere are many causes of lag. The parent was referring to the case of "I'm typing a bunch of data into a bunch of cells". Network connectivity should not (necessarily) cause lag in that in case: it should let the client side update without interruption, and then pass data over to the server as it is able. If network syncing is interfering with user text input, something is wrong with that design. Edit: The historical analogy would be like if you were entering data (offline) into your Lotus cells, but your computer would keep freezing up so the modem could reconnect. Somehow they kept those decoupled back then!
- mkagenius 10y agoIt ends in 2048(maybe before) -- Why call it a "law"? Probably easy to remember by giving a name, I guess.
- popey456963 10y agoThe article ends by saying "By the theorem, Koomey's law has the potential to be valid for about 125 years". One imagines that it could continue long after even this however with further ways of computations being discovered.
- tgb 10y agoReversible computation (which that 125 year number refers to) has to be done very slowly. There might be some applications where that would still be relevant, but it's pretty clear this trend don't last even until the 2048 mark, let alone for another 125 years and beyond. The Feynman lectures on computation have some good sections on reversible computation that I would recommend.
- Chronos 10y agoIn a lot of scientific and mathematical fields, "law" means "a mathematical relationship between two or more things that seems to hold under common circumstances". Take Newton's Laws. They're not true, as Relativity has replaced them, but they approximate certain regimes of reality, so they remain useful as shortcuts.
- quakeguy 10y agopi/2 years, i'm trying to make sense of this fact.
- mistercow 10y agoIt's a coincidence.
- quakeguy 10y agoOf course, it must be. My theories explaining this were mind-boggling, at least.
- syncsynchalt 10y agoIt's because π seconds is a nanocentury.
- sfeng 10y agoI found this linked to topic even more interesting: https://en.wikipedia.org/wiki/Landauer%27s_principle https://en.wikipedia.org/wiki/Landauer%27s_principle
- dredmorbius 10y agoThere's a whole slew of interesting tangents off that article along the lines of computational efficiency, yes. Recommended reading.
- 205guy 10y agoIndeed, the idea of information (bits) as entropy is fascinating to me too. And not just Shannon entropy, they're all related somehow. See https://en.wikipedia.org/wiki/Bekenstein_bound https://en.wikipedia.org/wiki/Bekenstein_bound And then there is the fact that life encodes and persists information. There was a recent HN thread that got me interested: https://news.ycombinator.com/item?id=13496133 https://news.ycombinator.com/item?id=13496133 I did read Gleick's "The Information" but was disappointed it didn't dig very deep into the concept. I got further following links on Wikipedia.
- tedsanders 10y agoIn that case, you may also enjoy Bennett's 1982 paper on the thermodynamics of computation: www.dna.caltech.edu/courses/cs191/paperscs191/IBMJTheorPhys(21)905.pdf That said, there are a lot of subtle assumptions wrapped up in the Landauer limit (related to the 2nd law of thermodynamics and the notion of 'erasure') and my personal opinion is that the limit is easily overrated before those subtleties are appreciated.
- mrfusion 10y agoIt brings up reversible computing as a way to not require any energy. What would a reversible computer look like? Could I run Firefox on it?
- beat 10y agoI find the idea of power limits to be fascinating. As computing becomes more distributed, more detached, more mobile, then power, not computation, will be the boundary. It's not just the cpu... it's the screen, and the antenna. A screen needs to produce a certain number of lumens of light to be readable. That provides a theoretical limit. An antenna needs to transmit clean signal over a certain range. That takes power, too. And the size of the device limits the size of the battery. How many joules of energy can we store in that physical space? We may be coming up on limits for mobile devices much harder and faster than we think. Of course, IoT devices can be better off by not supporting a screen, but communication is still a problem.
- dredmorbius 10y agoTaking your thought and running with it: Yes, energy/cycle is the ultimate limit, and imposes bounds on what we can do with computers. There are other factors, including dissipating of waste heat. Both those concepts are joined in Gene Amdahl's observations. He noted that in paralellisation, though you could extend this to any efficiency improvement, your efficiency bound is imposed by the unaddressable task component. For parallelisation, it's the nonparallel component, for energy efficiency, it's the non-CPU power draws. He also noted that everything ultimately comes down to a matter of plumbing (including heat dissipation). Screen tech has benefitted greatly from the transitions from paper => CRT => LCD (flourescent) => LCD (LED), and increasingly e-ink devices. Applications and devices which can utilise largely-static screens, where only state transitions require energising (as with e-ink and textual interfaces) have far less power draw than any emissive screen tech. Other peripherals -- input/output, including keyboards, touch devices, antennas, ports, etc., also play a role. Physical keyboards have advantages over screens, though audio input/output might address size constraints (and impose numerous others...). The possibility of passive antennas (see the 1960s Russian "shield" audio bugging device in the US Embassy in Moscow) could offer other options, assuming that a fixed station would have a power budget mobile devices wouldn't. There's been a lot made of small and adhesive solar PV innovations. I see the real use of that as offering the ability for very small computational devices to power and/or recharge themselves opportunistically when and as ambient light is available. Incorporating both battery storage and PV into designs -- say, an adhesive data-tracking and reporting label which could be attached to shipping packages -- as layers of PV, battery, compute, and antenna, would allow for very cheap monitoring of conditions (location, shock, temperature, humidity) for deliveries, at a cost of pennies, and without extensive engineering considerations. (The hackability of such devices might ... pose interesting considerations.) We're approaching a state where, theoretically, any device of more than a few dollars' value could have some integrated computational capacity, whether you like it or not.
- btreesOfSpring 10y agoit looks like Koomey's law will outlive the year 2038 problem[0]. 0: https://en.wikipedia.org/wiki/Year_2038_problem https://en.wikipedia.org/wiki/Year_2038_problem
- libeclipse 10y agoWhat do you mean by this comment? I don't see how the two are linked.
- btreesOfSpring 10y agoThey aren't directly linked. I just like the idea of cataloging all of the time bounded limits in CS. Reading the wiki entry and having forgotten the exact date for when Unix time comes to end, although knowing it is close, i figured others might enjoy seeing the 2038 date too. Based upon voting, I was wrong.
- dbcurtis 10y agoGood news for robots.
- hartator 10y agoI think it's not a fair game if we are going to find a new law every time progress stale in our industry.
- abecedarius 10y agoThe part at the end about the Margolus-Levitin theorem makes no sense to me -- that theorem gives a speed limit, while Koomey's trend is about energy use. Can anyone fill in the citation-needed?
- jwtadvice 10y agoThis is incredible. I followed this link down into the Margolus-Levitin theorem, which puts a physical limit to how much computation (entropy?) you can produce with a single joule of energy (6 x 10^33 operations/second). It seems that at some point the unit for powering computers would then have to be matter, since there's such an incredible amount of energy stored per newton.
- andrepd 10y ago>It seems that at some point the unit for powering computers would then have to be matter, since there's such an incredible amount of energy stored per newton. I'm not sure what you're trying to say but that sentence doesn't make sense.
- rsuelzer 10y agoYet my phone still won't hold a charge for more than three hours.