Stupid questions. (Closed apps and battery)

Discussion in 'Mac Basics and Help' started by novetan, Nov 24, 2010.

  1. novetan macrumors 6502

    Sep 3, 2010
    When more applications are opened but not actually running (sorry, not sure the right word, ie the small white dot at the dock besides each app is lit up but no working files or no web page is opened), will it increase the temperature and eating the battery?
  2. tkhiem macrumors newbie


    Jun 5, 2010
    Adelaide, Australia
    i'm a not a computer pro, but I think it will take up some of your RAM if you don't "fully quit" it. When more RAM is used, more power (i.e. battery) will be used, too.
    But I don't think it will dramatically decrease the battery life cos the app is too small and it only takes a bit of RAM (of course it depends on apps, but small apps like Preview shouldn't take too much of RAM).

    Please correct me.
  3. dissolve macrumors 6502a

    Aug 23, 2009
    You are correct. Not quitting an application stores its state in RAM, which is what allows you to access it very quickly. Actually, opening an application and fully quitting it still stores some of it in RAM. You can test this by opening a big application, quitting, and reopening.

    Storing information in RAM requires some power, but it is incredibly miniscule. Just think, when you sleep your computer, you are storing the state of all applications and the OS in RAM and in all of Apple's modern notebooks, this requires less than 2W. Basically, in theory you'd get less battery life, but it's so small that I doubt testing would verify this claim. There are so many other factors that I wouldn't worry about it at all. Quitting applications is useful if you're running low on RAM, not as a means to save battery life.
  4. novetan thread starter macrumors 6502

    Sep 3, 2010
    Thanks guys for insight. How about not quitting apps will it increase temp? Sorry, very trivial but Im just curious.
  5. ytk macrumors regular

    Jul 8, 2010
    The only way leaving applications running idle in the background would have any significant effect on anything is if you fill up your RAM completely. In that case, the system will spend a lot of time paging memory out from the disk, which will impact both overall performance (and hence, usable battery life) and temperature--the latter less than the former, but any disk access necessarily causes a decrease in battery life and an increase in temperature. You can generally tell when this is happening because applications you haven't used in a while take a lot longer to become active when you switch to them.

    As for how much memory idle applications use, it really depends on the application. Safari or Word can use up a fair amount of RAM when not in use--up to a few hundred megabytes. On a system with only 2GB of RAM, that's a pretty large chunk. Even 4GB may not be enough to handle it, depending on what you're doing. The best way to tell how much memory you're using is to install a memory monitor program like MenuMeters that lets you continually keep an eye on your RAM usage. If your free RAM ever drops down to below 100MB, it's likely that you're paging. To be sure, you need to check the number of pageouts (you can do this by clicking on the RAM menubar item in MenuMeters). If it's anything but 0, you can be certain that you either need more RAM, or fewer apps running.
  6. novetan thread starter macrumors 6502

    Sep 3, 2010
    Well, thanks for the detail explanation.

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