New RAM usage

Discussion in 'MacBook Pro' started by DWS1187, Aug 10, 2012.

  1. DWS1187 macrumors newbie

    DWS1187

    Joined:
    Nov 15, 2011
    Location:
    Kinston, NC
    #1
    Is this a normal situation the uptime is around 3 and 1/2 days no shutdown only sleep.

    Running Programs:

    Parallels Desktop 7: 4GB Windows 7 Pro
    iTunes
    Safari
    Mail
    Calendar

    Thanks just Curious :p
     

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  2. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #3
    No page outs, so you're not maxing out your RAM. As to what usage is normal, that depends on what you're running at any given point in time.
     
  3. Intell macrumors P6

    Intell

    Joined:
    Jan 24, 2010
    Location:
    Inside
    #4
    Completely and utterly normal. Mac OS X, as with most UNIX based operating systems, free ram is wasted ram.
     
  4. DWS1187 thread starter macrumors newbie

    DWS1187

    Joined:
    Nov 15, 2011
    Location:
    Kinston, NC
    #5
    Thanks. I am loving the 16GB. Just installed it a week ago. Running parallels windows 7 with 4GB of RAM is much better, before I had 8GB and it ran okay, but I was running around 7.8+ used with iTunes, Safari, Mail, Messages, Calendar, and Parallels Desktop 7 open and I didn't like that so I upgraded.:D

    On another note, does OS X use the RAM it's given? In other words will it efficiently use the RAM according to the total installed? I have witnessed Windows 7 using 800MB of RAM with 2GB installed and nearly double when using 4 GB of RAM on a desktop. I find this intriguing...almost like the computer doesn't care as much to conserve when it knows it has the RAM. Thanks again.:apple:
     
  5. stevelam macrumors 65816

    Joined:
    Nov 4, 2010
    #6
    of course it'll use the ram its given. whats the point if it couldn't? same with windows. fyi, assigning more cores to parallels is much more of a performance gain than going from 2gb to 4gb of ram. obviously this will also gimp your osx side.
     
  6. nontroppo macrumors 6502

    nontroppo

    Joined:
    Mar 11, 2009
    #7
    That is exactly what you want an optimised VM system to do. The same software will show very different memory footprints dependant on how much free+inactive RAM is available. Opera for example can go from <100MB to >700MB with the same pages depending on what you run it on.
     
  7. DWS1187 thread starter macrumors newbie

    DWS1187

    Joined:
    Nov 15, 2011
    Location:
    Kinston, NC
    #8
    I am using 2 cores of my i7 processor to run the Virtual Machine, do you think that's enough? Other that the fans running a 4000 to 6000 RPM while using a processor intensive program and the CPU on iStat reporting at or near 70something degrees Celsius, everything seems to operate well.

    So OS X will vary the RAM usage according to available RAM (makes sense), and is there a technical name of this RAM allocation process?

    I feel like i am full of questions today...

    oh and simsaladimbamba thanks for the link.
     
  8. nontroppo macrumors 6502

    nontroppo

    Joined:
    Mar 11, 2009
    #9
    It is so fundamental I think this is really just "memory management", free pages are allocated on request and the kernel will manage pages based on the number of free pages left, you can read much more detail here:

    https://developer.apple.com/library...tual/ManagingMemory/Articles/AboutMemory.html
    http://en.wikipedia.org/wiki/Page_replacement_algorithm

    And for a simpler version, aimed at Linux but just as applicable to OS X (replace the term "used" with "inactive", another slight wrinkle is OS X uses a unified buffer cache)

    http://www.linuxatemyram.com/index.html
     
  9. DWS1187 thread starter macrumors newbie

    DWS1187

    Joined:
    Nov 15, 2011
    Location:
    Kinston, NC
    #10
    nontroppo, thank you for the wealth of information. I love reading about things such as this. It answers my question perfectly.
     

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