Macbook Pro RAM - some data

Discussion in 'MacBook Pro' started by unkleE, Dec 19, 2013.

  1. unkleE, Dec 19, 2013
    Last edited: Dec 19, 2013

    unkleE macrumors newbie

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    Dec 19, 2013
    #1
    I have read a lot of posts about the need or advisability of buying a new Macbook Pro with 8 GB or 16 Gb of RAM, and reading many different opinions.

    Obviously everyone's needs are different, but my interest was in the idea of "future-proofing". So I decided to see how well future proofing worked in the past.

    So I checked out the dates each version of OS X appeared and the minimum and recommended RAM for each one. Graphing these up showed some interesting facts:

    • The graphs are exponential (i.e. they plot as straight lines with the Gb axis shown as logarithmic), with RAM doubling about every 2.5 years.
    • The gap between "Recommended" and "minimum" is also about 2.5 years (because the recommended is generally double the minimum).
    • Thus, if you want to get 5 years life out of your Macbook Pro, you need to get about double the recommended RAM or 4 times the minimum.
    However these conclusions come with a big proviso - that you want to keep upgrading your OS whenever a new version is released (and presumably upgrade your other software too).

    If you are willing to work within the capabilities of the OS and software you use when you buy your Macbook Pro, then it will become unusable much more slowly, but eventually it will be impossible. This is for several reasons:

    • Most of us connect to the internet, and as time goes on, websites, video formats, etc, upgrade their requirements, and eventually an old OS and browser cannot cope.
    • Likewise, most of us receive emails from friends with attachments, and gradually these attachments cannot be opened using an old OS and the software that goes with it.
    (We have been using an old eMac with 640 Mb RAM running Tiger for almost 10 years. It still works, allows us to use the internet and emails, but now it cannot play video or open lots of email attachments, and we cannot upgrade the relevant software because the Mac can't cope with it.)

    So we can draw another approximate conclusion from my graph - if you are willing to stay with the same OS, you'll probably get a maximum of about 7 years out of your Mac if you start with the recommended RAM, and about 9 years if you double the recommended RAM - if other things don't fall down in the meantime.

    Applying this information from past performance to the future is doubtful. Perhaps the technology will change completely (not just quantitatively) in the future, perhaps RAM specs will hit some brick wall like CPU speed did, who knows? But the past is the only guide we have, so I hope this info might assist somebody.

    My conclusion in a nutshell:

    1. If you're happy to upgrade to a new Mac every 2-3 years, get the recommended RAM for your usage.
    2. If you want to keep upgrading the OS and want to replace your Mac every 5 years, buy 4x the minimum RAM or double the recommended RAM for your usage.
    3. If you are happy to stay with the same OS and want to only upgrade to a new Mac when absolutely necessary, get double the minimum RAM at least.

    For most users therefore, 8 Gb will be fine if 2 GB is considered the minimum and 4 Gb is the recommended, but if you need more than 4 Gb now, get 16 Gb for the future.
     
  2. cheesyappleuser macrumors 6502a

    cheesyappleuser

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    #2
    Interesting theory.
    Somehow it convinced me more than any other topic on this matter.
     
  3. Wishbrah macrumors regular

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    Oct 20, 2013
    #3
    Interesting read. It's nice reading a RAM speculation thread with some predictive data to back it up
     
  4. unkleE thread starter macrumors newbie

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    Dec 19, 2013
    #4
    Just thought I'd post the graph.

    [​IMG]

    The red and blue dots are the stated minimum and recommended RAM sizes (taken from Wikipedia and Apple), plotted against the publication date for the 10 OS X versions so far (10.0 Cheetah through to 10.9 Mavericks). The red and blue lines are the exponential line of best fit (straight line with a log scale for the Y-axis, as you can see). Thus this information is quite objective.

    The green dots are the three times we have purchased (or are about to purchase) a Mac - an eMac purchased 2003 and upgraded to 640 Mb RAM and running 10.4 Tiger, a Macbook with 4 Gb RAM running 10.6 Snow Leopard and (about to purchase) a Macbook Pro with 8 GB RAM running 10.9 Mavericks This information and the line through it is obviously very subjective.

    Finally, the info on running a Mac with the original OS until it can no longer cope with the internet is based on our experience with the eMac, which has only recently become unusable, 10 years after it was purchased.

    I hope the graph makes sense and helps people.
     
  5. BigHam macrumors member

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    Mar 23, 2013
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    Australia
    #5
    Very nice thread indeed. I'm going with the theory of doubling my current ram usage on my next machine so I can get it to last that extra year.
     
  6. MartinAppleGuy macrumors 68020

    MartinAppleGuy

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    Sep 27, 2013
    #6
    Great post! Really deserves more reads :) Thank you for plotting this out. I had a rough idea of OSX upgrade RAM requirements working somewhat like this but never thought much more about it. Thanks for the full info.

    1 thing though, could you please re-post the graph above but with the RAM on the Y-axis being in direct variation/proportion (ie - the spaces between 1Gb, 2Gb, 3Gb, 4Gb.. are all equal to each other). Thanks :)
     
  7. Meister Suspended

    Meister

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    Oct 10, 2013
    #7
    Really nice post. Ive been looking for something like that before.
    Sadly I think a lot of people will read this and buy ram upgrades they dont need because they misinterprete.

    Obviously the ram requirements have gone up over the years and its nice to see it in a graph.
    But all requirements go up over time in a similar fashion. CPU, GPU and discspeed!
    So if you want to really futureproof your machine you might as well max it out in every aspect.
     
  8. IronManFanatic macrumors newbie

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    Jan 11, 2014
    #8
    Hmm, maybe I should opt for the 16GB RAM. My RAM usage tends to fluctuate normally around the 4-6GB mark at the moment (This is generally under a heavy load), and this is on Windows (without multiple Spaces/Desktops).

    Going by this graph, 16GB doesn't seem so roomy in a few years (Especially with 4k about to make a mainstream entrance, and websites becoming ever more graphic intensive with auto-background videos playing). I presume Windows notebooks will start coming with 12GB RAM chips soon enough, and then eventually 16, but at the moment, 16GB seems to be a luxury (and excessive for most).
     
  9. unkleE thread starter macrumors newbie

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    Dec 19, 2013
    #9
    Here it is (same graph but with Y axis linear scale rather than log).

    [​IMG]

    The three lines are the same as before - the exponential lines of best fit.

    ----------

    Like my original post says, you probably only need the extra RAM if both (1) you want to keep upgrading the OS, and (2) you aren't going to buy a new Mac within 4-5 years.

    I went with 8Gb, not 16.
     
  10. MartinAppleGuy macrumors 68020

    MartinAppleGuy

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    Sep 27, 2013
    #10
    Thank you for that :) Again, very interesting. Thanks for the post. What was the exact spec of the Mac you bought and how long do you plan to keep it?
     
  11. maflynn Moderator

    maflynn

    Staff Member

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    Boston
    #11
    That's basically how I buy computers. I usually go with #1 since I used to buy computers every 3 years but that cycle has changed, so now I'm in category 2 :)

    Nice work on the graphs and leg work
     
  12. mneblett macrumors 6502

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    Jun 7, 2008
    #12
    Most useful analysis I've seen on this subject -- given all the 8 vs. 16 threads, this should be a sticky!

    And FWIW, my experience is that the "preferred" amount climbs even faster.

    I purchased my late '13 with 16 GB in part to have "enough" RAM later in life (I go about ~5 years between purchases). Four months later I'm already finding myself regularly going over 8 GB RAM (even recognizing "Inactive" RAM is essentially "Free" RAM) -- several open programs in OSX and running Win 8.1 under Parallels gets me well over 8 GB pretty easily. For me, going with 16 GB was the "right" choice because it is now clear that I have "bought" myself some "margin" before hitting any RAM-caused performance reduction or bottleneck.

    Of course, everything I do would also run under 8 GB, just with more disk swapping. With an SSD, that is less noticeable than with a spinning disk, so memory swapping is more "livable" today than 4-5 years ago -- making the 8 vs. 16 choice even harder.

    If funds were tighter, I would have seriously considered staying with 8 GB RAM. However, because RAM is no longer user-replacable, I suspect that would cost me more in the long run because I would end up upgrading sooner than planned, when the ever-increase RAM demands begin to impact performance sooner rather than later.

    Of course, that's just my needs and my turn-over time. If I traded up every 1-2 years, I could "live" with 8 GB while I wait for the "base" RAM level to rise and the cost of the "option" RAM tiers to come down. So as noted by the OP, it still all comes down to individual usage patterns/plans.
     
  13. MartinAppleGuy macrumors 68020

    MartinAppleGuy

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    Sep 27, 2013
    #13
    I would say that if you wish to run vm's, add 4Gb to double the reconnected RAM (4+the equation above). That is the only place I feel like you need more than 8Gb of RAM.
     
  14. Meister Suspended

    Meister

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    Oct 10, 2013
    #14
    To add some of my observations i took a screenshot of my activity monitor a moment ago:
    [​IMG]
    As you can see it is possible to push the boundaries of 8gb on a rmbp.
    I am not running any VMs. There are several raw (Nikon D4, D610) files opened in Ps, Lr, Intensify and preview. Also a bunch of jpegs from a Canon Powershot. Word documents, pages docs, chrome , safari (20+ tabs) netflix running, and some minor rendering in imovie, and so on ...
    The memory pressure even managed to go into the red before this shot was taken.
    By all means this is not normal usage because i just left everything open over the last few days and i work with two different user accounts.
    It was still very responsive and only beach balled for a few seconds while opening imovie.
    I don't think a normal user will ever exceed 8gb (even 4gb) but if you need to leave tons of different media editing apps and files open simultaneously I think 16gb of ram is worth a consideration.
     
  15. MartinAppleGuy macrumors 68020

    MartinAppleGuy

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    Sep 27, 2013
    #15
    Lol I only ever have 1 program running at a time on my iMac! Are you sure I made the right decision with 8Gb of RAM? Or should I have bought a maxed out Mac Pro with 64Gb of RAM? *sarcasm

    On a more serious note, I have seen someone using a 16Gb MacBook Pro running Mavericks. He was able to use all 16Gb, and then have 8.5Gb compressed before it even touched Swap! A total of 24.5Gb is just amazing, that algorithm Apple used for the RAM compression is probably my most favourite feature of Mavericks. What spec is your MacBook?
     
  16. IronManFanatic macrumors newbie

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    Jan 11, 2014
    #16
    Does Activity Monitor display all running processes? The highest memory usages of those seen processes do not seem too high at all; to be exceeding 8GBs.
     
  17. TheEnthusiast macrumors regular

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    Aug 22, 2013
    #17
    If you click on individual processes, you'll see the real memory.
     
  18. Meister Suspended

    Meister

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    Oct 10, 2013
    #18
    My screenshot doesnt show all processes. I could scroll down way further.
     
  19. augustya macrumors 68000

    augustya

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    Feb 17, 2012
    #19
    So Guys I intend to do keep a rMBP 15" for atleast a Minimum of 5 Years My current RAM usage just about already reaches 7 to 7.5 GB on a 13" rMBP with a 8GB of RAM, so If I am planning to get the 15" rMBP upgrading to 16 GB RAM Makes more sense right guys ?
     
  20. MartinAppleGuy macrumors 68020

    MartinAppleGuy

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    Sep 27, 2013
    #20
    When you are using 7-7.5Gb of RAM, how much App Cache is used, how much compressed memory is used? Pst a screenshot of Activity Monitor after a restart, then another screenshot when you have common programs open.
     
  21. augustya macrumors 68000

    augustya

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    Feb 17, 2012
    #21
    iStat Menus is showing me that Data ? is that not conclusive ? It says after 4 hours of my usage only 50-100MB of RAM left ! Which is I use that much 7-7.5GB of RAM in almost 4 Hours of using the rMBP !
     
  22. ru7hl355 macrumors regular

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    Aug 31, 2013
    Location:
    Scotland
    #22
    Doesnt Mavericks try and use all memory available to keep things snappy, then start to compress once it does begin to reach a the maximum? my RAM is always pretty much 7.5 to 7.9gb and thats with multiple open apps (Photoshop, PHPStorm, Chrome(10+ tabs), iTerm, Mail, Adium, SublimeText, Messages and 2 external HD monitors connected). haven't ever noticed it lagging....

    I also dont think iStat gives enough of a in depth reading since Mavericks was released due to the new memory management.
     
  23. MartinAppleGuy macrumors 68020

    MartinAppleGuy

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    Sep 27, 2013
    #23
    Look at activity monitor. It is in the Utilities folder in Launchpad. OSX Mavericks only consumes 1.8Gb of RAM. It is all the App Cache that makes that number much bigger. Remember, that using almost all of your RAM will be much faster that using the smallest amount. Just post a screenshot (Cmd shift 3).

    ----------

    Correct. OSX Mavericks only really uses 1.8Gb of RAM. When in Activity Monitor, take away the App Cache number from the Used RAM to see how much the OS is really using.
     
  24. augustya, Feb 13, 2014
    Last edited: Feb 13, 2014

    augustya macrumors 68000

    augustya

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    Feb 17, 2012
    #24
    Here you go...This is a screenshot of my activity monitor after 6 Hours of Heavy use...What does it say ?[​IMG]
     

    Attached Files:

  25. MartinAppleGuy macrumors 68020

    MartinAppleGuy

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    Sep 27, 2013
    #25
    You are not pushing the system RAM fully. Another 4Gb could still be compressed before any page outs. I always recommend getting more RAM if the RAM pressure is red, but your RAM pressure is still very low, as you are not pushing your system. If you plan to keep a new Macbook Pro for 5 years, I would still say 8Gb of RAM would be fine. What programs do you run at the same time?
     

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