OS 10.2 & Ram, Why So Much For Nothing?

frank_tfrank_t
Posted:
in macOS edited January 2014
Well I have a new PowerMac Dual 867Mhz that i got 2 weeks ago. I'm very happy with it as i updated from a 7300/180 PowerMac....which let me say is one hell of a big Step :eek: :eek:



Anyways on too what this post is about....Ram and Mac OS 10.2. I got 768MB of DDR ram in this PM and when i go to Terminal and do the 'top' thing i see that it doesn't even use %50 of my ram with 5 apps runing.....what it does use is a hell of alot of my hard drive space for VM which i don't understand why it does when there is still alot free Ram to be used.....but no it just sits there unused.....i got a VM that is around the 2.5GB mark when i still have %50 of my REAL Ram free....WHY?



I hate to see how much REAL ram get's unused with those peoples Macs that have 1GB (or like the new PM Mac's 2GB) of real ram in them....when in the end it doesn't get used much at all...



Only when that day comes that like everyone here knows....you open EVERY app on your mac....but even if you did.....how could your brain multi task with that many apps anyways?



Frank_t

Comments

  • Reply 1 of 6
    amorphamorph Posts: 7,112member
    OS X is capable of using all your RAM. It reserves any that your applications aren't using to cache recently accessed files and recently launched applications - you can think of it as virtual memory in reverse. The swap space is basically a fixed size. Just because there's 2.5GB reserved for it doesn't mean that it has actually swapped out 2.5GB worth of logical memory while leaving your real RAM half idle!
  • Reply 2 of 6
    frank_tfrank_t Posts: 428member
    OK!!!!! <img src="graemlins/lol.gif" border="0" alt="[Laughing]" /> <img src="graemlins/lol.gif" border="0" alt="[Laughing]" /> <img src="graemlins/lol.gif" border="0" alt="[Laughing]" />



    Frank_t



    thanks for your HELP!!!
  • Reply 3 of 6
    ghost_user_nameghost_user_name Posts: 22,667member
    Oy. The subject of memory with OSX comes up about once a month it seems. The first thing you need to do to understand OSX's memory system is to forget EVERYTHING you think you know about memory management from OS9. Those rules and methods do not apply to OSX. Really, it's that different.



    Amorph's explanation was exactly right. Just because there's 2.5GB of VM listed, that doesn't mean 2.5GB of memory is actually being used. It just means that the system has allocated that much to be available, if necessary.



    Here's my obligatory links to John's article:

    <a href="http://arstechnica.com/reviews/01q4/macosx-10.1/macosx-10.1-6.html"; target="_blank">http://arstechnica.com/reviews/01q4/macosx-10.1/macosx-10.1-6.html</a>;

    <a href="http://arstechnica.com/reviews/01q4/macosx-10.1/macosx-10.1-7.html"; target="_blank">http://arstechnica.com/reviews/01q4/macosx-10.1/macosx-10.1-7.html</a>;



    The article is specifically about 10.1, but the same logistics about memory still apply to 10.2.



    [ 09-14-2002: Message edited by: Brad ]</p>
  • Reply 4 of 6
    torifiletorifile Posts: 4,024member
    [quote]Originally posted by Brad:

    <strong>Oy. The subject of memory with OSX comes up about once a month it seems. The first thing you need to do to understand OSX's memory system is to forget EVERYTHING you think you know about memory management from OS9. Those rules and methods do not apply to OSX. Really, it's that different.



    Amorph's explanation was exactly right. Just because there's 2.5GB of VM listed, that doesn't mean 2.5GB of memory is actually being used. It just means that the system has allocated that much to be available, if necessary.



    Here's my obligatory links to John's article:

    <a href="http://arstechnica.com/reviews/01q4/macosx-10.1/macosx-10.1-6.html"; target="_blank">http://arstechnica.com/reviews/01q4/macosx-10.1/macosx-10.1-6.html</a>;

    <a href="http://arstechnica.com/reviews/01q4/macosx-10.1/macosx-10.1-7.html"; target="_blank">http://arstechnica.com/reviews/01q4/macosx-10.1/macosx-10.1-7.html</a>;



    The article is specifically about 10.1, but the same logistics about memory still apply to 10.2.



    [ 09-14-2002: Message edited by: Brad ]</strong><hr></blockquote>



    Maybe we should link to commonly asked questions/issues about OSX at the top of this forum's page? It would save people the trouble of getting all worked up and posting then hearing possible misinformation while those who know the answers get in here. Just a thought. Maybe that was a suggestion.... <img src="graemlins/hmmm.gif" border="0" alt="[Hmmm]" />
  • Reply 5 of 6
    rodukroduk Posts: 706member
    [quote]Originally posted by frank_t:

    <strong>I got 768MB of DDR ram in this PM and when i go to Terminal and do the 'top' thing i see that it doesn't even use %50 of my ram with 5 apps runing.....what it does use is a hell of alot of my hard drive space for VM which i don't understand why it does when there is still alot free Ram to be used.....but no it just sits there unused.....i got a VM that is around the 2.5GB mark when i still have %50 of my REAL Ram free....WHY?</strong><hr></blockquote>



    One way of looking at it is that under OSX, you are always using virtual memory, but that doesn't mean pages are actually being swapped out to disk. The OS can't suddenly switch virtual memory on when there is no physical memory free, it has to be on already (with its allocated disk space), which is why switching it on under OS9 requires a reboot for it to take affect.



    [ 09-14-2002: Message edited by: RodUK ]</p>
  • Reply 6 of 6
    thinkingdifferentthinkingdifferent Posts: 1,604member
    Remove 50% of the memory and see how your Mac performs.
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