RAM usage

Discussion in 'MacBook' started by PowerBookRelic, Apr 21, 2009.

  1. PowerBookRelic macrumors 6502

    Joined:
    Mar 7, 2008
    #1
    Why would my computer page out if I have 400 mb of RAM free? My swap is 5mb/64mb, what does that number indicate? Also, my page in is 162,080 page out 25.
     
  2. alphaod macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #2
    Page out means it's moving stuff out of RAM; that happens when you close programs, etc.

    If you have a lot of Page ins, then that's a sign you don't have enough memory.
     
  3. pesc macrumors regular

    Joined:
    Jan 20, 2006
    #3
    It is possible to map files in memory and use paging for bringing the contents in to memory. A program may choose to do so instead of using normal read/write to the file. But this is also what happens when you start any program; the code of the program is mapped to memory and brought in as the program executes.

    This means that page ins is quite normal and does not necessarily mean that you don't have enough memory.

    It also means that page outs also can happen normally and does not necessarily mean that you are low on memory.

    When you close a program the memory it occupied will become inactive or free. This operation will rarely need paging out.

    It is simply not easy to just look at the numbers and deduce whether you should buy more memory. Sorry.

    Having 25 page outs is really nothing to worry about.
     
  4. clyde2801 macrumors 601

    clyde2801

    Joined:
    Mar 6, 2008
    Location:
    In the land of no hills and red dirt.
    #4
    You've only got 512 megs of ram (going from the machines in your sig), so you could probably assume more ram is a good idea. Come to think of it, you could almost always assume more ram is a good idea.

    You should be able to stick 2 gigs in it relatively cheaply, and see if that makes a difference in your numbers.

    BTW, why is this in the macbook/ibook section and not the macbook pro/powerbook folder?
     
  5. PowerBookRelic thread starter macrumors 6502

    Joined:
    Mar 7, 2008
    #5
    This is on my black MacBook 2.4 C2D with 2 GB. I guess I am not overly concerned with 25 page outs if that does not seem like a big deal. My uptime is 4 days if that makes a difference. With the iStat widget, what does the bar on the bottom of the memory section refer to? And what does the swap figure (e.g., 5mb/64mb) mean?
     
  6. Macmel macrumors 6502

    Joined:
    Feb 7, 2008
    #6
    That description is not correct. I have 4 Gb of RAM, I have over 105000 PI and 0 PO and I am no even close to run low on memory.
    I read somewhere in MR that having more than 10-15% PO relative to PI means that you might need more memory (or having more memory will help you).
    In the OP specific case, with only 25 POs, I seriously doubt he will benefit from more RAM
     
  7. PowerBookRelic thread starter macrumors 6502

    Joined:
    Mar 7, 2008
    #7
    That makes sense. I do not think that I need more RAM, I just thought it was odd that it PO with free RAM available. Anyone have any more info on the Swap number, or the bar at the bottom of the iStat widgit.
     
  8. pesc macrumors regular

    Joined:
    Jan 20, 2006
    #8
    I'm not sure what swap numbers you mean. Can you explain further or attach a screenshot?

    Same with iStat (which I don't use). A screenshot might help.
     
  9. PowerBookRelic thread starter macrumors 6502

    Joined:
    Mar 7, 2008
    #9
    Here is a screen shot of my iStat...
     

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  10. bozz2006 macrumors 68030

    bozz2006

    Joined:
    Aug 24, 2007
    Location:
    Minnesota
    #10
    wow, your CPU runs cool! the CPU on my aluminum macbook is usually 120-130 degrees Farenheit.
     
  11. pesc macrumors regular

    Joined:
    Jan 20, 2006
    #11
    The first swap number is the amount of space used in your swap file(s). The second number is the total size of all your swap files.

    You can see your swap files by examining the folder /var/vm (type in the path by using the "go to folder" command in the Go menu item (sorry I don't use an english Mac so I can't be more precise)). New swap files are created when needed. They can also be deleted automatically by the system when not needed anymore.

    The bar at the bottom measures how much memory is "used" (wired+active). Inactive or free memory is not regarded as "used" here.
     
  12. VSMacOne macrumors 601

    VSMacOne

    Joined:
    Oct 18, 2008
    #12
    Lol, I'm glad i just ordered a 4GB Ram kit :D
     

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  13. bozz2006 macrumors 68030

    bozz2006

    Joined:
    Aug 24, 2007
    Location:
    Minnesota
    #13
    you haven't turned your computer off in three weeks?!?
     
  14. dentedG4 macrumors member

    Joined:
    Jun 18, 2007
    #14
    Not to hijack this thread or anything, but i noticed on your istat you have 100% battery health and 65 cycles. I on the other hand have 93% health and 90 cycles.

    Whats a quick rundown on your battery use? do you leave it plugged in at full charge often? do you mostly run off the battery? do you calibrate often? Do you run your battery down most of the way before you plug it in? Thanks!
     
  15. PowerBookRelic thread starter macrumors 6502

    Joined:
    Mar 7, 2008
    #15
    That is the same command for the English Mac. As far as the swap file is concerned, is it best to not mess with it, just let the OS run the SWAP, I would assume.

    Also - I agree 100% battery life is awesome. I notice as I let my battery run down my battery life goes up 1 or 2 percent, but then when it gets all the way down and I plug it in, it goes back down :confused:
     
  16. Matek macrumors 6502a

    Joined:
    Jun 6, 2007
    #16
    The absolutely best thing you can do is forget about it. Don't overanalyse it, don't think you should often calibrate it, don't take it out just because you have a powerplug available, etc. It's made to be used that way and very often you may cause more harm than you think by intentionally charging/discharging it (some wisdom by Dan the man). If you do that and at the same time don't leave it in the sun, you should be fine.

    The measurement is more of an approximation based on voltage, etc, so it's just standard deviation.
     
  17. VSMacOne macrumors 601

    VSMacOne

    Joined:
    Oct 18, 2008
    #17
    Yup. I pretty much just put it to sleep when I carry it in my backpack, and I haven't had the need to shut it down in a while.

    Apple recommends to have it plugged in as much as possible, but to make sure that you give the battery some use, and calibrate very 4-6 weeks. My regular day looks like this: plugged in over night, I unplug it in the morning to take it to work with me, then at work pretty much plugged in all day long (except for a meeting or something), then back at my house I'll use it on battery around the house for a little bit, but if I'm around the charger, it'll be plugged in. I'm NOT saying this is the ONLY way to guarantee 100% health, but it's the way I've done it, and you can see the results above :D

    Don't let it go all the way down, if you can help it. Running the battery down without actually doing the Calibration steps will in fact hurt the battery health.
     
  18. pesc macrumors regular

    Joined:
    Jan 20, 2006
    #18
    Correct, you absolutely should not mess with the swap files. I don't think OS X will let you anyway. I just mentioned it because it can be interesting to know how things work on OS X.

    The system will create larger and larger swap files when needed; 64M, 128M, 256M, 512M, 1G (but not 2G). When the system suddenly decides it needs to create a large swap file on the disk you will get a beach ball spinning for a while; quite a while if you have a slow or nearly full disk.
     

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