MBP RAM Upgrade - Free RAM

Discussion in 'Mac Basics and Help' started by zw-gator, Oct 12, 2009.

  1. zw-gator macrumors 6502a

    zw-gator

    Joined:
    Oct 23, 2005
    Location:
    Canada
    #1
    I currently have 2GB of RAM in my MBP and according to iStat I only have 40mb of RAM free.

    I've ordered 4GB of RAM and it should be here by next Monday.

    Anyway, will I experience any speedups? Does my system slowdown when I'm low on free RAM?
     
  2. gr8tfly macrumors 603

    gr8tfly

    Joined:
    Oct 29, 2006
    Location:
    ~119W 34N
    #2
    You have to include "inactive" memory, too. That's also available for application use - it's just cached incase you relaunch the same app or use the same data.

    The main thing you want to look at is the number/size of pageouts. If it's large, relative to the pageins, then more physical RAM can improve performance by reducing how often a page gets swapped to the HD.

    This might help:
    http://support.apple.com/kb/HT1342
     
  3. zw-gator thread starter macrumors 6502a

    zw-gator

    Joined:
    Oct 23, 2005
    Location:
    Canada
  4. zw-gator thread starter macrumors 6502a

    zw-gator

    Joined:
    Oct 23, 2005
    Location:
    Canada
  5. gr8tfly macrumors 603

    gr8tfly

    Joined:
    Oct 29, 2006
    Location:
    ~119W 34N
    #5
    It doesn't look too significant, but if those pageouts all happened at once, you might notice some slowdown.

    You can also use "top" in Terminal - it will show the number/sec. For instance: 88012(0) pageins, 1428(0) pageouts, where the number in parenthesis is events per second. If you have it running, while opening and using your apps, you might see if it's a few or many per sec. Again, it's the rate which will determine whether you will notice a performance hit.

    edit: Looking at the Activity Monitor data, it doesn't look significant - the ratio of in vs. out is very small. You have a total of 745MB [essentially] free. Of course, since you've close apps, it's not a good snapshot of your usage.

    Also, keep in mind the data in iStat or Activity Monitor is cumulative. If you just booted up and got the pageouts all at once, it's more significant than if the system had been up and running for weeks and the pageouts occurred sporadically.
     

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