Activity monitor reports 3.90 of 4G ram in use

Discussion in 'MacBook Air' started by carizma22, Mar 20, 2015.

  1. carizma22 macrumors member

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    Houston, TX
    #1
    From what I have read in this forum, the consensus is that most people don't need 8 gig ram. So I experimented with having multiple pages in Safari, Adobe Pro, Mail and MS Word open – this is what I typically have when I am working. In the activity monitor, it shows that anywhere from 3.60 to 3.90 of my 4 G ram is in use, unless I am misunderstanding the readout (attached). Can anyone help me understand this? I am going to buy a new MBA, to want to understand if I really do need to upgrade to 8G or not. Thanks.
     

    Attached Files:

  2. motrek macrumors 68020

    Joined:
    Sep 14, 2012
    #2
    This is normal. OS X does its best to allocate all physical memory to whatever programs you have running, and/or file cache.

    The important thing to note is that the memory pressure graph shows green, meaning that if you do something that requires more memory, it's readily available.
     
  3. bradl macrumors 68040

    bradl

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    #3
    Just because the activity monitor shows that 3.9GB of 4GB is being used, doesn't mean that it is actually IN USE. The memory that is used is either buffered, and/or cached, preventing an application from having to make a call out to the hardware to allocate memory to it. It would simply pull it from cache instead of making the additional call, preventing I/O contention.

    Additionally, that memory could be buffered ahead of time, similar to how Youtube would buffer the stream of a video so you could watch it without any pausing or interruption.

    Finally, like in Windows, Linux, and other OSes, there is a swap partition that pages get swapped in and out of memory for.

    I currently have Safari, Postbox, GIMP, XQuartz, SublimeText, iTunes, and the App store running, and I show 3.6GB out of 4GB being used, with 475MB unused. Yet I have, according to the Activity monitor, 5GB of Virtual memory (swap) used, but my apps are only using 1.7GB. The remaining 1.9GB is buffered or cached.

    So while it states that nearly all of your memory is being used, it doesn't mean that it is actually in use.

    BL.
     
  4. motrek macrumors 68020

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    #4
    Yes. Put another way, there's the amount of memory that an application is using, and then the amount that the OS allocates for it.

    The OS always tries to allocate more memory than the app is currently using, because the app could start using more memory at any given time. If the memory is already allocated, then the memory can be used immediately. Otherwise, stuff has to be swapped around and there's a performance penalty.

    So there's no reason not to allocate all available memory to whatever's running, regardless of whether or not it needs it.

    So unfortunately when Activity Monitor says that a certain amount of memory is "used" it really means that memory is just allocated, and to my knowledge there's no good way to tell how much memory the apps are really using. The memory pressure graph seems to be the best indicator of... well, memory pressure.
     
  5. carizma22, Mar 20, 2015
    Last edited: Mar 20, 2015

    carizma22 thread starter macrumors member

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    #5
    So it is the "memory pressure" that matters: it is now flicking back and forth from green to a little orange.

    What I am finding is that the more stuff I have open, the slower everything is. There was a lag in my typing this. And each new program I have opened has taken much longer to load.

    Is that ram memory related, or is it related to the speed of the processor of my late 2010 MBA (1.6 GHz), or is it because I only have 2 gig left out of my 120 gig flash storage? Or something else?

    Thanks for your answers. I have had a Mac of one sort or another since 1984 when I had one of the first Macs with 128K ram. But I have only ever learned how to do what I needed to do with each one, and not learned how things work. But I want to make informed choices here on out.

    ----------

    So in the activity monitor where it says "app memory", in my case right now 1.34 gig, is that not what you are talking about?
     
  6. carizma22 thread starter macrumors member

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    Houston, TX
    #6
    20 gigs movies

    When I go to "about this mac" and click on storage, it tells me 20.82 Gig is allocated to movies, but I can't find on my computer except for a few minutes of my grandkids playing. is it possible that they take up that much space?
     
  7. motrek macrumors 68020

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    #7
    If you're seeing orange in the graph, that's not great. You would benefit from having more memory. If you aren't actively using some apps, you can try closing some and see if that helps things.

    If you are seeing memory pressure, then your computer is offloading some RAM (memory) onto your SSD (flash storage). If you only have 2GB of storage available on your SSD then that could definitely cause slowdowns. I would recommend doing what you can to free up space on your SSD. (See below.)

    You have more history with Apple than I do. I started with a Macintosh SE in 1987. :)

    No, that's just how much memory the OS has allocated for apps, instead of the operating system itself or the file cache. All of those numbers aren't really relevant. The OS manages all that stuff so you don't have to worry about it.

    ----------

    I would recommend downloading a shareware program called Disk Inventory X.

    This will go through your drive and present you with a nice list and graphic showing what is taking up space on your drive.

    You might be surprised and find things that you don't need anymore and are no-brainers to delete and free up space.
     
  8. Meister Suspended

    Meister

    Joined:
    Oct 10, 2013
    #8
    Yellow memory pressure is not good and only having 2gb free left on your ssd is not good either.

    I recommend you clear up some space.

    Also, can you post the rest of your activity monitor and maybe describe in more detail what apps you are running simultaneously?

    ----------

    That is a very general statement. The specs you need in your mac depend on your individual use.
    If your activity monitor is already yellow, I strongly suggest you opt for 8gb in you next mac.

    Nevertheless I have a hard time believing you are merely running word, safari, mail and adobe pro. These apps should not cause such high memory pressure.
     
  9. carizma22 thread starter macrumors member

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    #9
    You are absolutely right, I wasn't. I opened a bunch of other programs to see how far I could go before seeing yellow. I'm almost never going to need to have all of these things open, so I realize that I mostly likely do not need 8 gig ram.
     
  10. carizma22 thread starter macrumors member

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    #10
    Thanks for all your help.

    I did download Disk Inventory X, but when I tried to open it, I got a dialog box with the message, "You can't open the application "Disk Inventory X" because Power PC applications are no longer supported."

    This is the 2005 version 1.0 beta for OS 10.3 or newer. Is there a more recent version and if so can you offer me a link to go find it? Or is there something I can do about the power pc apps?
     
  11. carizma22 thread starter macrumors member

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    #11

    Solved it myself. Found a universal version. Now I see that something called TextEdit Document is using 18.6 GB. What is that and can I do anything about it? And iTunes document is using 18.5 GB. Ate these really documents or are they programs. I can see iTunes using space, but TextEdit?!!!
     
  12. lazydog macrumors 6502a

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    Cramlington, UK
    #12
    Hi
    I think your next Mac should definitely have 8GB! When I got my Air 4 years ago 4GB was plenty, but over the last year and a bit I have found myself pushing that 4GB more and more, not necessarily by me running more or different apps but rather the same apps consuming more resource (or so it seems to me). Right now I have 5 tabs open in Safari and those sites are consuming between 100 and 200 Mbytes each! Who knows what will be the hit for an average website a year or two down the line. I think Yosemite does a terrific job of memory management and it squeezes as much as it can out of 4GB, but the cost is that after a certain point it slows your Mac down. In those situations the simple answer is to add more memory... simple and cheap. But now that memory is soldered and not upgradeable, it makes the cost of a memory upgrade very expensive (you need to purchase a new Mac). So, yes the sensible option is to go for 8GB now and not have to worry or have regrets later on.

    b e n
     
  13. motrek macrumors 68020

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    #13
    I wouldn't worry about it. I see the same thing. I assume it just thinks all text files are "TextEdit Documents" or that's the default if it doesn't know the file type.

    More important is digging down in the file tree next to that window pane to see which directories/files are taking up all your drive space.
     
  14. tmarks11 macrumors 6502

    Joined:
    May 3, 2010
    #14
    Only 2GB left is going to make your machine crawl. Just a note, your SSD probably has failed sectors and that has reduced the capacity of your SSD.

    My wife's 60 GB SSD on her 2010 MBA went from 30 GB free to 1 GB free overnight and the machine was like molasses. I replaced it with a new Transcend JetDrive 500 and it is all good now (20 min of work). The process was seamless; the new SSD clones everything on the old SSD with absolutely no pain.

    http://us.transcend-info.com/apple/jetdrive/
     
  15. carizma22 thread starter macrumors member

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    #15
    Thanks for the idea of the Transcend. I will keep it in mind if my new machine runs out of space. I have serendipitously discovered that I can afford to buy a new one, so I will go for the 2015 on the grounds that it is going to have to last me for years and years. I would still be using my 13" Macbook that I bought in January 2009 if it hadn't been stolen in October 2010. That was a great laptop, but I love my MBA.
     
  16. motrek macrumors 68020

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    #16
    Whaaa? Something went wrong and wrote a log file that was too big and your solution, instead of to delete the file, was to replace the drive?!
     
  17. tmarks11, Mar 22, 2015
    Last edited: Mar 22, 2015

    tmarks11 macrumors 6502

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    #17
    It was already making the machine crawl before that happened. 5 year old SSD in a 2010 MBA, without TRIM. Not a big surprise.

    And it wasn't a monster "log file" as you claim. Nice try.
     
  18. SlCKB0Y macrumors 68040

    SlCKB0Y

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    #18

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