Question about iMac and its memory.

Discussion in 'iMac' started by definitive, May 21, 2009.

  1. definitive macrumors 68000


    Aug 4, 2008
    I was wondering if it handles memory differently from Windows. Here's what I mean:

    I start up the system, and have it running all day. Throughout the day I may use it and load up several applications such as Adobe CS4, FireFox, Colloquy, Messengers, and other stuff. After I'm done using them, I close them. When I go to Activity Monitor to see how much RAM I have free, it says 800mb-1gb. Is this normal? On Windows the RAM is usually freed once the application is closed, and Activity Monitor only shows the basic apps running in the background, and they can't be taking more than 500mb of physical RAM...
  2. sammich macrumors 601


    Sep 26, 2006
    When you open and close a program, most of that RAM stays as inactive memory. Basically it sits in waiting in the event that you reopen that application, it will load in a fraction of the usual time. If you run out of free memory because inactive has used it all up, some of that inactive may be written to your hard disk as swap space depending on how long it has been inactive.

    I know how you feel. I upgraded my RAM in hopes of reducing my swap usage, but it's probably only gotten worse.
  3. definitive thread starter macrumors 68000


    Aug 4, 2008
    that didn't really make sense to me. you gave me a lesson on how memory works, not if it's used differently on a mac than it is on windows.

    example: my windows system has 2gigs of ram. windows takes up about 400megs. when i load up a ton of apps, the ram shows up as 1gig free in task manager. as soon as i unload those apps, the free ram shows as 1.6gigs.

    in mac it doesn't go back to whatever it was when i first booted it up (say for example 3.5gigs free).

    i'm just wondering if it's normal.
  4. jtgotsjets macrumors 6502


    May 20, 2004
    Lawrence, KS
    This may be below you, but you do know that on macs, closing the window does not exit the program like it does on windows- it continues in the background. You must actually quit.
  5. definitive thread starter macrumors 68000


    Aug 4, 2008
    doesn't apple+q quit the application? i thought that as long as i quit that way that the application was closed...
  6. annk Administrator


    Staff Member

    Apr 18, 2004
    Somewhere over the rainbow
    Yes, apple+Q quits the application. I think the poster before you was referring to the fact that on a Mac, just closing a window (by clicking the red button in the upper left corner) doesn't quit the application.
  7. angemon89 macrumors 68000


    Feb 5, 2008
    The place where Apple designs stuff
    Yes it's normal. Sammich answered your question when he said that after you close an application, the RAM that was being utilized by that application now becomes inactive RAM.

    Inactive RAM is essentially free ram that is in reserve.

    It will not show the same amount of RAM as when you first booted up because of this inactive RAM.
  8. dp9300 macrumors newbie

    Jun 2, 2009
    rochester ny
    is it worth upgrading imac memory?

    hello i have a 3.06 24 inch imac and i bought it with 2gb of memory but hoping to upgrade it. but my question is, is it actually worth putting 4gb in? will i actualy see a diffrence?
  9. Hellhammer Moderator


    Staff Member

    Dec 10, 2008
    Yes, it is worth it. It will make everything faster because system and applications have more RAM to use and they don't have to store data to much slower hard drive.

    I assume that you have the '08 model with DDR2 RAM? It can take officially 4GB and unofficially 6GB of DDR2 RAM but I recommend 4GB, it'll be enough for you. Crucial is good place to buy.
  10. uberamd macrumors 68030


    May 26, 2009
    Take Inactive and Free, add them together, and you have your 'free' available RAM. A optimal OS uses RAM whenever it can because it is faster than the disk. Having a ton of free RAM can actually be worse for performance.

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