Apr 20

When your computer is running a bit slowly, how can you tell if getting more memory will help?  The short answer is that if you have little or no ‘free memory’ or if your ‘page-out’ count is high, then you need more RAM. Here’s how to check those two things on any Macintosh running OS X.

  1. Go to your Applications/Utilities folder. (Click on your desktop so that the finder is active then hold down Apple-Shift-U, this will open your ‘utilities folder.)
  2. Open ‘Activity Monitor’ – it will probably be the top-most application in the Utilities Folder.
  3. Press Apple-1 to make sure that the main window of Utility Monitor is open.
  4. Click on the ‘System Memory’ tab at the bottom of the window. This will display a little pie graph of how much memory you are currently using. It will look something like this:

There are two important items to take note of ‘Free:’ and ‘Page outs:’

Free tells you how much free memory you currently have available to use –  the higher the better.  If you have no free memory you should get more RAM.

A Page out  means your computer has run out of memory and had to use some of the Hard Disk instead of RAM. (This is the equivalent of your brain being too full so you have to write your thoughts down on paper to free up some headspace) This DRAMATICALLY slows down your computer.

To quote from Apple:

Moving data from physical memory to disk is called paging out (or swapping out); moving data from disk to physical memory is called paging in (or swapping in)… Extended periods of paging activity reduce performance significantly; such activity is sometimes called disk thrashing.

Tip: Page outs occur when your Mac has to write information from RAM to the hard drive (because RAM is full).  Adding more RAM may reduce page outs.


Some Examples:

Here’s a mac with plenty of RAM (12G) – lots of Free RAM (green) and zero Page outs.

Here’s a mac with just enough RAM (8G) – a relatively little Page out Count (339MB) and some free memory (green).

Here’s a Mac that needs more RAM (it only has 640M!) – note the High Page Out Count (1010524) even though it currently has some ‘free’ RAM.

This Mac definitely needs some more RAM! Practically no free memory  AND High Page-out Count. (1GB!)  Performance will be suffering badly. I would add at least another 4G Ram, maybe 8G more to bring it up to 12G.

In OSX Leopard rather than giving a ‘count’ of page in and page outs, it gives a size in GB  of the amount of RAM that has been paged in or out. The numbers are smaller but the same principals apply.

In OSX Lion there is a new entry called ‘Swap Used’. (See the last picture above). This  is a count of how much Disk Space your computer is using as RAM and it’s a good rough estimate of the minimum amount of  extra RAM you need. Eg If your Swap used is 4G then get AT LEAST 4G more RAM.

Where to buy more RAM.

If you do need more memory  I recommend buying it from Crucial. They have good prices and reliable RAM. I’m in Australia and it usually arrives in about a week. They have a great memory lookup tool for all Apple Computers where you choose your model and it shows you exactly what memory you need.  The memory chooser tool looks like this:

First choose ‘Apple’ where it says ‘Choose Manufacturer’

Secondly select your mac when it says ‘select product line’ (e.g. iMac or Macbook etc)

Finally select the exact model (e.g. Early 2011 i7 27″ iMac”)

It will then show you the options you can buy.


Note (Jan 2013): I have signed up as a Crucial affiliate partner.

Click here to get 5% off your crucial order (and I get 2% commission)!

105 Responses to “Does my mac need more memory?”

  1. Dee says:

    I need some help. I am not much of a computer person. My desktop is a about 3 years old and is now telling me that the start up disk is full. I followed the instructions at the top checking the utilities folder and the circle graph shows very little memory. Also I cannot save any documents in Word. I would like to delete some stuff if I can rather than adding more RAM. Can I do this and how?
    tks alot

  2. Jeet says:

    On the Disk Usage part of my activity monitor, it shows in green (free space) that I have 148.73 GB of unused space. The mac I have is OS X version 10.4.11. It has always caused me problems…. I hope you can help me. First of all I can’t download or save anything from documents to emails. Safari quits unexpectedly whenever I go on to youtube or even google. (When this happens it says: Safari quit unexpectedly. Reopen, Quit, or Report to mac). Some of the games I’ve downloaded through a CD quit as well. (When this happens it says: safari could not download the file because there is not enough free disk space. Try deleting documents or downloading to another file.) But how can I not have enough free space when the disk usage shows that I have 148.73 GB of free space!!! Please help as I have had this problem for more than 2 years. Thanks.

    • admin says:

      I’d post this question to the Apple Support Forums, or ring Apple as it sounds like a specific problem that might take a bit of troubleshooting.

      Try ‘repair permissions’ from Disk Utility. That’s the first step for most problems.

      Go to your ‘downloads’ folder in your documents folder in your home directory, do ‘Get Info’ and check your user (Me) has read and write permissions.

  3. betsy says:

    This was extremely helpful, exactly the information I needed. Thank you for posting.

  4. Katy says:

    i just got my macbook pro today, it said that there was 500 GB of space, but now my system memory looks like the last screenshot above. Is this a problem?

  5. Arthur G says:

    My page outs is high 2.02GB and swap used is also 2.02GB but i have 1.15GB free out of my 3.75GB. What does this mean? Why is my page outs so high if i have a lot more free space than shown in the examples? Is there a way to clear out the page outs?
    P.S. page ins:13.93GB not sure what this means

  6. Bruce A says:

    I just purchased 16GM for an iMac 2011 2.7Ghz from Crucial. $126CDN incl.customs/tax.
    Works like a charm. Bit of overkill but for this price it is worth it. Highly recommend Crucial.

  7. Ki says:

    I came across this article. Its clearly explained the differences, but it doesn’t show the reader how to determine when page out is too much,…Here is my situation, macbook pro mid 2010. stock RAM installed 4GB. OS.
    Free: 1.33GB
    Wired: 852.3MB
    Active: 1.34GB
    Inactive: 500MB
    Used: 2.66GB
    VM size: 215GB
    Page ins: 1.31GB
    Page outs: 905 MB
    Swap used: 543.0 MB
    HD: 250GB. Used: 167/ Free: 81GB

    I’ve noticed my mb pro decline in performance. I don’t run heavy apps, mac is mostly used for web browsing and 1 game (Startcraft II). I seldom use final cut pro and aperture. What can i do to increase performance ?


    • James Mauro says:

      The article did tell you in later operating systems you look at “SWAP USED”. I would suggest hooking up a secound screen or using the extend desktop option, placing the activity meter in that screen or open it open in another page in your mac as you play starcraft. With the current information you need to have at least an extra 543mb. Which sense you have 2 slots that means you need a pair of 4gb sticks. remmber also that its not just the Mhz of the ram (your computer can only put so much power) but also the latency (CAS) the lower the CAS number on the ram, the less number of computer clock scles before it preforms again. Ideal the ram would be at CAS 1, but typically depending on your MHZ of your ram your lucky to see 7 most versions will have a CAS of 9-9-9-28 I suggest that you get this version with the maximum MHZ your computer can hold for ram. Also you said your computer is slow, I suggest buying an external drive, placing any file/video you do not need constantly on it, (speeds of my 4TB WD USB 3.0 external is around 130mbs (several times faster than most non 4k video require) Than what you need to do after transferring all that data is to delete the data/files that where transferred to the external from your 2010 mac. Now your computer works like new, if you did this before you bought the ram, now you may not need to buy the ram, but it would be nice to do it anyway. The only reason you should ever have to upgrade a MAC is because you want to do something it could never do, not because the computer is old. They are very reliable systems, which is why i always suggest them. Your Drives should never be completely full, that slows down any drives performance on an old or a new computer, figure leaving at least 25% of free space especially on an Operating system drive. Although the performance on a Movie drive may drop from 135mbs to lets say 100 mbs (maybe more maybe less) when completely full, if the video file is less than 5mbs you could never tell the speed decrease.

  8. Brian says:

    Thank you for this article!!!! SO informative and insightful. It answered all my questions and MORE. I am definitely bookmarking this and sending to friends or whoever has questions regarding RAM/memory in the future. I’ll be referring back to this in the future as well. Kudos!

  9. Don says:

    Hi, I had already added RAM to my 2 GHz Intel Core Duo, taking it to the maximum it can hold – 2GB. However, the Activity Monitor shows Free 60MB with 1.9 GB Used and Page Outs of 5GB.

    Is there a way that I can reduce the Used/Page Outs count and therefore increase the Free count?


    • Wayne says:

      Yes, close some apps or open less apps. Make sure you don’t have too many dashboard widgets open. Use Activity Monitor to see what’s using up your RAM.

  10. Dave says:

    If your running Lion I can sympathise. I have recently installed Lion on my late 2006 iMac which max ram is 3GB (even tho you can fit two 2GB chips it only recognises 3).
    What you can do as I have found out from trawling the Apple support pages is to run some of your RAM hungry apps in 32 bit mode e.g. Mail, Safari. Info is on Apple https://discussions.apple.com/thread/3238726?start=0&tstart=0.
    Also you can stop your Mac remembering its App settings and automatically opening everything when you start up and taking all your RAM. This keeps the Apps in 32 bit mode and you don’t have to keep shutting them down top reopen in 32bit(tip from ‘MIssing manualMac OS X Lion’. Can’t post copyright material).

    Finally I have found a free App in the App store “Memory Freer” which uses Activity monitor and tells you when your RAM is dropping and also will free up RAM that Apps are holding onto, but not using.

    Using these I have got my page outs with 10 big apps open down to very low numbers or normally 0 during light normal usage.

    I myself am not a Techie, but a long term Mac user. Also I have found out that I cannot upgrade my Mac any further as Mountain Lion won’t run on my Mac or Macbook Pro. Guess it maybe new computer time soon.

    Hope this may help. D

  11. Josh says:

    I have a question? I just upgraded the ram in my imac (2011) with memory I purchased from OWC 16GB (4x4GB). I opened the activity monitor and it says that 13 GB of ram are currently wired. That seems a bit high. I don’t have many applications running right now and its not running that slow but I don’t know why 13 GB of RAM would be wired at this point. It says I only have 267 MB free.

  12. Jon says:

    I’m using Adobe Flash player, and I’m getting an icon (grey circle with an ! in the middle) that states I need more memory to run a specific application — I’m using Safari. Yet I have 2.89 GB of free space. What is an ideal amount of free space for a system to safely run applications? Do I have enough?

  13. Mark says:

    My imac keeps freezing whenever I run iTunes. At first the computer will freeze every 40 seconds and over time freeze every sec. I’ve called Apple and they can’t find anything wrong with it. If I reset the PRAM it helps for a bit but then it happens again. Any advice? I have a 2.5ghz intel core i5, 4gb ram. Do I need more ram? Any help is greatly appreciated.

  14. jul says:

    Macbook pro just bought not long time ago
    Free:1.03 Gb
    Wired: 890MB
    Inactive:509.2 MB
    VM size:179.79GB
    Page ins: 23.54 GB
    Page outs: 28.21 GB
    Swap used: 2.24 GB

    Can you help me to find out do i have problems with my mac. Thank you for help i just start using Mac, so i does’t know mac really good.

  15. jonathan says:

    V helpful article. Was starting to see the spinning wheel more and more on my early 2011 macbook pro, particularly after upgrading to lion. Came with 4gb ram but i have lots of apps open at the same time including VM running windows and was starting to think mac just not up to it. Read this, checked that memory was low and relying on hard drive, bought 16gb ram upgrade kit from Crucial for peanuts…..wham! I have my rocket back, everything sharp as a razor, haven’t seen hideous spinning wheel since.

  16. sam says:

    My swap used is 59GB! Page Outs: 47GB, Page Ins: 74GB

    Can i even install that much ram? I have a 2011 MBP with a 256GB SSD and currently only 4GB of ram. I’m a graphic designer so I run adobe suite most of the time which i understand is quite a heavy load. Could that 59GB figure be accurate? Seems outrageously high…

  17. David says:

    Hi there, have a mac mini 2,3 GHz duo core i5 (Lion OS – Mid 2011).
    I’ ve installed Windows 7 professional ( for project courseworks) and mainly for gaming. I have 2 Gb of RAM and wanted to know whether a RAM upgrade to say, 8GB will improve gaming experience in terms of graphics, and smooth running? Thanks.

  18. Diko says:

    Please help. At the Activity Monitor of my MacBook Pro, under System Memory it says my free memory is 2.77 G (green). I am currently saving/importing songs to my iTunes from my CDs for later transfer to my iPod. Will my MBP’s memory be affected to the point of slowing it down?

    The capacity of my iPod is 32G. How do I fill it up with songs from my MBP iTunes if I can only save 2.77 G worth of songs in my MBP iTunes?

    Under Disk Usage (at the activity Monitor), however, it says there is still 250 G? Is this what my MBP will use up for my songs or the System Memory?

    Pardon my ignorance. I am a newbie on these things. Thanks.

    • Lee Dale says:

      Hi Diko.

      As you’ve discovered, to the right of ‘System Memory’ in your Activity Monitor is a tab called ‘Disk Usage’. Songs will be stored on your HD which is shown under this Disk Usage tab. As long as you’ve got space there, you’ll be golden.

      In other words, understanding the difference between RAM (temporary, and for applications to run) and hard disc space (where your files are stored), you’ll know that opening iTunes and asking it to import your songs from a CD to the HD will use RAM to perform those tasks, but the actual files are stored on the HD and will not impact RAM once the import task completes.

      Hope that helps.

  19. Molly says:

    Thank you very much for these instructions. I just placed my memory upgrade order with Crucial. BTW, I had 20.3 MB free, and swap was 1.40 GB. No wonder my laptop was soooooooo slow!

  20. [...] decision: Based on my MacBook’s symptoms and checking a few statistics in the Disk Utility tool, I decided I would upgrade my computer’s memory, aka RAM (random [...]

  21. [...] decision: Based on my MacBook’s symptoms and checking a few statistics in the Disk Utility tool, I decided I would upgrade my computer’s memory, aka RAM (random [...]

  22. John says:

    Thank you! very helpful and clear. Plus the crucial recommendation is spot on, same thing that I have been told by everyone including Apple.
    thanks again.

  23. Scott says:

    Thanks for the article, useful for confirming.

  24. Brandon says:

    Hi All- I would love some help…I went to the Apple store and the genius determined that my ram was not strong enough…I doubled the ram and installed the new, but everything is still running slow…

    Free: 35MB
    Wired: 533MB
    Active: 768MB
    Inactive 2.68 GB
    Used 3.95 GB
    VM sie: 118GB
    Page ins 1 GB
    Page outs: 651 MB
    Swap used: 9.6 MB

    Any suggestions on what the issue could still be?


  25. Philip Cowan says:

    Wow, thanks for this. I was sitting on Amazon wondering whether to press the button and buy more RAM (Crucial, as it happens) and thought I would just check if I really needed it. Your article answered that question very well (yes I do — sitting on a Swap used of 5.36GB).

    I really appreciate the care and attention you have put into this article (I teach Journalism at a university in the UK).

    Best of luck to you, Wayne.

  26. R00bot says:

    Mine is a 4gig RAM macbook pro (year old now) and it says page outs: 6.47 gigabytes.
    Is this bad? What do I do?

  27. Dave says:

    Hey thanks for this article. I had a question and you actually had basically an exact screenshot of my system! More RAM it is!

  28. C Winkler says:

    I’m so glad I found your Mac site! Thank you, Brother! Your post helped me so much! I’ll be a frequent visitor from now on. God bless you!

  29. Thank you! EXCELLENT explanation of what to look for and what it means. I need a memory upgrade…going to your affiliate link now!

  30. kate says:

    I am not good at computers. Went through your tutorial and it says I have 587 MB of free space. My page outs are 100.00 KB. The graph shows a decent hunk of green and at the bottom it says 2 GB. Is more memory needed? The other day I tried to open excel and it said it couldn’t open it because I didn’t have enough memory so that seems to suggest I do, but yet going through your exercise made me think I had enough. Help!

  31. Chrish says:

    I’ve just upgraded my iMac from 4GB to 12GB of memory. Do I now need to do anything to optimize it at all, or is it OK to just leave as is?

  32. indirbak says:

    very much thank you

  33. Tim says:

    Haha I was wondering why my mac was so slow. I got my 17″ pro for a year and a half now and was really unpleased that the performance was so bad already.
    Turns out that I got 30GB page outs at the moment. Thanks for this article, I immediately ordered in 16G in stead of the 4GB I use now.

  34. JoJoHants says:

    Hi, used this help the other day which really did highlight a lot of page outs, so installed Grand Perspective to clean out some old stuff and used an app to tidy up loads of duplicate files (result form shifting over from a windows pc about 18 months ago).

    So went back into my Utilities folder today to see if it had helped and did I still need to get an external hard drive, but the thing doesn’t look the say any more??

    There is no graph, no tab at the bottom?? There are tabs at the top identified as CPU / Memory / Energy / Disk / Network

    So I assumed they had just removed the word ‘system’ from the memory tab.
    The info looks pretty similar, but in a different format, but there is no FREE info & no PAGEIN/OUTS info.

    Can anyone help please??? I dont want to buy something I may not need, but would like to understand this new format. Wish I could add a screen print for you.

    Thanks from one un-technical female!

  35. Geertje says:

    Thanks! Been searching for info to be able to decide whether I could safely install Maverick. I definitely need more memory, and gonna check if my mac can handle more RAM (my mac gets overheated pretty quick), before I even start to think of upgrading to Maverick.

    I own a mac book 10.6.8, from 2006,
    processor: 2GHz core 2 Duo,
    memory: 2 GB 667 MHz DDR2 SDRAM

    System memory
    - free ca 23 MB
    - page outs: 65,6 MB to 93 MB

    Gonna check my activity monitor more often from now on, to see which (useless) programs/plugins are open / taking away too much memory space.

  36. Stephan Keen says:

    A nice detailed article on whether you need a Mac RAM upgrade. Thanks for sharing. I would also advice that you carry out a SMC (system controller reset) and PRAM reset to see if your Mac will speed up, before splurging on memory that can be quite expensive these days.

  37. Stephan Keen says:

    Oh, by the way, for anyone interested in instructions on how to carry out a SMC and PRAM reset, here are good instructions. http://machmachines.com/macbook-pro-running-slow-heres-how-to-fix-it/

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