Does my mac need more memory?

When your computer is running a bit slowly, how can you tell if getting more memory will help?

If you run out of free memory then your computer will be forced to use some of your hard disk as memory, which is VERY SLOW because hard drives are much slower to access than your computer’s RAM.  It’s not just a matter of saying ‘8 GB’ is enough because the amount of RAM you need will vary according to your Mac model and the programs you use.  Here’s how to check if you have enough RAM.

How to check your Memory on a Mac

With El Capitan Apple have introduced a very simple graph based on colours to let you know if you have enough RAM or not. Do this during the middle of using your computer for what you normally use it for. Don’t do this as soon as you start your computer as this won’t give a good indication of your normal usage. Better still, check it at various times over a few days.

  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 graph with the memory pressure. It will look something like this:

If there is any red in the memory pressure you need more RAM.  Red means your performance is taking a hit because your computer needs to use the disk drive for memory.

If the memory pressure is green you have enough memory (like the screenshot above).

If the memory pressure is yellow it may be worth monitoring over a few days to see if it goes into the red.

Checking your memory on older versions of Mac OS

On older versions of Mac OS the display looks more 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 head space) This DRAMATICALLY slows down your computer.

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 principles 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.

You can’t buy any RAM. It needs to be Apple compatible. It’s worth getting good quality RAM to avoid problems. Currently my 2 favourite places to buy RAM are or OWC Computing. My Mac mini has 16GB of Crucial RAM in it at the moment.  I’m in Australia and it usually arrives in about a week. OWC might be the better option if you live in the USA.


They have a memory lookup tool for all 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.

OWC – Macsales

Another reliable source of good Mac RAM  is Other World Computing, also called

Why RAM affects your computer’s speed.

RAM in your computer is like the paper sitting on your desk. The information is easy and fast to access. Your Hard Disk is more like a filing cabinet, it takes a bit longer to retrieve information.

When your desk gets too cluttered you need to spend some time moving things in and out of the filing cabinet, which slows things down.

You don’t need to be able to store everything in your computers memory, it’s good to have a hard disk, but if you don’t have enough memory then your computer will need to access your hard disk too much and this can slow things down.

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.


140 responses to “Does my mac need more memory?”

  1. I’m totally perplexed. My 2010 mac pro 6-core has 16GB of ram and I’m paging out. Current apps are Adobe Lightroom (real mem 2.36GB) and Photoshop (real mem 3.3GB). There’s 4GB of inactive ram and usually more yet I’ve done 6GB of paging out in the past few days. Confused. VM is 235GB

  2. Sean, I’m in a similar boat, and I’m totally confused.

    I’ve got 12GB of RAM, and since my last reboot, I haven’t run anything but Mail, Safari, and a couple of other small items, with my free RAM never dropping below 9GB.

    But I’ve got about 1GB of page outs. Can anyone explain this?

  3. Sean and Robert… yes that is strange behaviour – Page outs with lots of free RMA. It seems that there could be a problem with Snow Leopard Memory use. Check out this thread:
    I say seems because I haven’t seen this myself – I only just googled it then.

    This may be fixed in the latest Snow Leoopard 10.6.5 so I can only suggest you update to 10.6.5 and see if that fixes it.

  4. fluke

    just added a ssd (flash drive) in place of my hd.
    my computer if flying now.

  5. al

    I upped from 2 to 4 on my macbook recently, but the green free stays small. I guess I now have a big blue inactive, but the machine doesn’t work any faster. Should i goto 6? or will it just give a bigger blue inactive?

  6. ben

    Before rushing out to upgrade your ram, use onyX (free from apple – do a google search) to fix permissions and run maintance. (you can also repair permissions through the dik utility first aid tool which is in the utility folde, which itsel is in the applications foder.). Fixing permission may appear to freeze for ages (an hour) – but let it finish, reboot and away you go.

    you should do this as often as everytime you intstall a third party app, as they can reek havok with your perissions, making your mac grind to a slow and painful death.

    after this your mac should run as quick as it did when you bought it.

    if not- upgrade ram… but iif you just go ahead and get better ram without sorting out the underlying issues with permissions you will neve get your machine as fast as it should and cold be.

    hope this helps

  7. Molly

    I don’t know if this is related to RAM, but I’ve been having this problem for a few weeks now and no other Mac users that I’ve asked have ever faced this. But whenever I try watching a video from the internet, it almost always freezes. BUT the audio still plays fine. It used to only be with Youtube videos, but now almost any internet video will freeze. Could it be because I need more RAM? Please help!! Thank you :)

  8. lolly

    I’ve got a MacBook 6,1
    I want to buy and install Photoshop but the system requirements are 2GB + extra during installation….
    My Mac only had 2GB to start with…I’ve just checked the System Memory and it says I only have 192.3MB free….
    Do I have to purchase more RAM before I buy Photoshop? I know it may sound dumb…but how do I add more RAM to it…does it have to be done by a Mac technician?

  9. Meto

    I have a problem with my mac pro. All my files and folders been transfered to an external memory but it still shows free memory only 1 gb and used 69gb. Please if any one can help.

    Thank you,

  10. Reem

    Hi, i’ve just purchased my first Mac and i mostly use my computer for school. So my university offers microsoft programs for free. but when i tried installing it, it stopped at a certain point and then it says theres zero kb available..
    what exactly does this mean i need to do?

  11. Very informative article. Thank you. However, it still does not explain the issue I am having and why I stumbled onto this post. For the past week I have been trying to update my OS from 10.6.6 to 10.6.7. I cannot get there through the standard route–using “Software update” in the Apple menu because I get an error message telling me there is not enough free space on my disk. When I check Activity monitor it shows I have 5.2 GB free and 0 page outs.

    I am (I think) able to circumvent this problem by downloading the update directly from Apple (it is downloading now) and I plan install it from my desktop. I do not understand why I am getting that message or what to do about it.

    Signed, Stumped at the end of the road in Costa Rica.

  12. karlina

    my mac says that i no memmory but i keep on deleting stuff…but it stills says”no memory”help if you can reply very soon!

    1. Deleting files doesn’t free up more memory, it frees up more Hard Drive space.
      Quitting running programs or re-starting your computer frees up more memory.

      Files are like your filing cabinet, where you store information long term. Memory is like your desk space, where you work on things. Free memory is like free space on your desk. Pulling files out of your filing cabinet and putting them in the bin won’t give you more desk space. Getting a bigger desk (more memory) or putting away what’s on your desk (quitting programs) frees up desk space.

  13. Bruno

    I just put in an extra 8GB of Ram in my G5 Mac Pro. It previously only had 2 GB – so that should bring it up to 10 GB. When I oprn about this Mac – it tells me it only has 2GB of memory. Is there a way to find out exactly how much Ram my computer now has?

    1. Turn off, jiggle ram, then power up, ram is faulty or not in properly or wrong kind of ram.

  14. Authentic Jordans For Sale

    my mac says that i no memmory but i keep on deleting stuff…but it stills says”no memory”help if you can reply very soon!

  15. Blackbird

    I have a 4gb Macbook Pro 2010 13″ 2.66 ghz. While I have no programs open, or nothing running in the background, is it normal to have the Used memory at 1.3gb? Seems kinda high to me! I’ve had computers with only 2gb and ran things just fine, but if my MBP is using 1.3 idle, thats not right. I’ve had issues with freezing too, which sounds like it might be a bad memory issue?

  16. Sheila

    My “System Memory” tab says I have 665MB of free space but when I go to disk usage it says I have completely full and have no free space. My computer won’t even let me save a file of homework. I dont know what to do!!!!!

  17. gh

    I came across this forum while searching to try and find why my Macbook runs hot and uses battery fast. This only occurs some of the time. From checking the Activity Monitor I noticed that Parallels (Windows emulator) is using 100% of my available memory. I assume that all other programs create pageouts. I see nobody has mentioned Parallels so it may not be the problem but I thought I’d throw it out. I don’t use Parallels a lot so I may uninstall it as I think it is loading on its own sometimes, depending on what work I’m doing.

  18. Mark

    I doubled my RAM to avoid creating lots of swap files. It helped, but I still create swapfiles even though I have 8BG of RAM and I never use more than 6GB. Shutting off the Apple Dynamic Pager did stop the computer from creating swap files in OS 10.6, but the Wired Memory displayed in Activity Monitor gradually grew to sizes I have never seen before. Using iFreeMem did nothing to convert Inactive Memory or the increased Wired Memory back into Free Memory. So far my best solution for avoiding slowdowns from swapping is to just restart the computer every week or so.

  19. Luke

    Hey thanks for this, this is a wonderful article and just saved me TOOOOONS of money, your awesome man!

  20. Greg

    Upgraded my ram in my MacBook pro to 8gb from the standard 4…. No noticeable difference in performance… Upgraded the Hd to an SSD…. And now it flies ;)

  21. Dee

    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

    1. This is hour hard drive full – not lack of RAM – delete some files! See this article:

  22. Jeet

    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.

    1. 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.

  23. betsy

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

  24. Katy

    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?

  25. Arthur G

    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

  26. Bruce A

    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.

  27. Ki

    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 ?


    1. James Mauro

      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.

  28. Brian

    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!

  29. Don

    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?


    1. 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.

  30. Dave

    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
    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

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