Optimized Storage in macOS Sierra and later* can save space by storing your content in iCloud and making it available on demand. When storage space is needed, files, photos, movies, email attachments, and other files that you seldom use are stored in iCloud automatically. Each file stays right where you last saved it, and downloads when you open it. Files that you’ve used recently remain on your Mac, along with optimized versions of your photos.

* If you haven't yet upgraded to macOS Sierra or later, learn about other ways to free up storage space.

Find out how much storage is available on your Mac

Choose Apple menu  > About This Mac, then click Storage. Each segment of the bar is an estimate of the storage space used by a category of files. Move your pointer over each segment for more detail.

Click the Manage button to open the Storage Management window, pictured below. This button is available only in macOS Sierra or later.

Manage storage on your Mac

The Storage Management window offers recommendations for optimizing your storage. If some recommendations are already turned on, you will see fewer recommendations.

• Samsung ram Memory Upgrade DDR3 PC3 12800, 1600MHz, 204 PIN, SODIMM for 2012 Apple MacBook Pro's, 2012 iMac's, and 2011/2012 Mac Mini's (16GB kit (2 x 8GB)) 4.6 out of 5 stars 279 $54.00 $ 54.
• Upgrade the memory of nearly any iMac, MacBook Pro, Mac Pro, or Mac mini. Save money by trading in your original memory chips for a cash rebate.
• Speed for Mac systems. A memory upgrade is the fastest, easiest, and most affordable way to get more performance out of your Mac system. Standard DDR3 modules help Mac systems reach speeds up to 1600 MT/s, and DDR3L modules start at 1866 MT/s.

Store in iCloud

Click the Store in iCloud button, then choose from these options:

• Desktop and Documents. Store all files from these two locations in iCloud Drive. When storage space is needed, only the files you recently opened are kept on your Mac, so that you can easily work offline. Files stored only in iCloud show a download icon , which you can double-click to download the original file. Learn more about this feature.
  
• Photos. Store all original, full-resolution photos and videos in iCloud Photos. When storage space is needed, only space-saving (optimized) versions of photos are kept on your Mac. To download the original photo or video, just open it.
  
• Messages. Store all messages and attachments in iCloud. When storage space is needed, only the messages and attachments you recently opened are kept on your Mac. Learn more about Messages in iCloud.

Nov 06, 2018 The general rule of thumb is to always use Mac-specific memory for your Mac. That doesn’t mean you have to buy it from Apple specifically, but it does mean the memory must be listed as being compatible with your specific Apple system. If not, you’re just figuratively rolling the dice, you’ll probably lose, and your Mac won’t work.

Storing files in iCloud uses the storage space in your iCloud storage plan. If you reach or exceed your iCloud storage limit, you can either buy more iCloud storage or make more iCloud storage available. iCloud storage starts at 50GB for $0.99 (USD) a month, and you can purchase additional storage directly from your Apple device. Learn more about prices in your region.

Optimize Storage

Click the Optimize button, then choose from these options.

• Automatically remove watched movies and TV shows. When storage space is needed, movies or TV shows that you purchased from the iTunes Store and already watched are removed from your Mac. Click the download icon next to a movie or TV show to download it again.
  
• Download only recent attachments. Mail automatically downloads only the attachments that you recently received. You can manually download any attachments at any time by opening the email or attachment, or saving the attachment to your Mac.
  
• Don't automatically download attachments. Mail downloads an attachment only when you open the email or attachment, or save the attachment to your Mac.

Optimizing storage for movies, TV shows, and email attachments doesn't require iCloud storage space.

Empty Trash Automatically

Empty Trash Automatically permanently deletes files that have been in the Trash for more than 30 days.

Reduce Clutter

Reduce Clutter helps you to identify large files and files you might no longer need. Click the Review Files button, then choose any of the file categories in the sidebar, such as Applications, Documents, Music Creation, or Trash.

You can delete the files in some categories directly from this window. Other categories show the total storage space used by the files in each app. You can then open the app and decide whether to delete files from within it.

Learn how to redownload apps, music, movies, TV shows, and books.

Where to find the settings for each feature

The button for each recommendation in the Storage Management window affects one or more settings in other apps. You can also control those settings directly within each app.

• If you're using macOS Catalina, choose Apple menu  > System Preferences, click Apple ID, then select iCloud in the sidebar: Store in iCloud turns on the Optimize Mac Storage setting on the right. Then click Options next to iCloud Drive: Store in iCloud turns on the Desktop & Documents Folders setting. To turn off iCloud Drive entirely, deselect iCloud Drive.
  In macOS Mojave or earlier, choose Apple menu > System Preferences, click iCloud, then click Options next to iCloud Drive. Store in iCloud turns on the Desktop & Documents Folders and Optimize Mac Storage settings.
• In Photos, choose Photos > Preferences, then click iCloud. Store in iCloud selects iCloud Photos and Optimize Mac Storage.
• In Messages, choose Messages > Preferences, then click iMessage. Store in iCloud selects Enable Messages in iCloud.

• If you're using macOS Catalina, open the Apple TV app, choose TV > Preferences from the menu bar, then click Files. Optimize Storage selects “Automatically delete watched movies and TV shows.”
  In macOS Mojave or earlier, open iTunes, choose iTunes > Preferences from the menu bar, then click Advanced. Optimize Storage selects “Automatically delete watched movies and TV shows.”
• In Mail, choose Mail > Preferences from the menu bar, then click Accounts. In the Account Information section on the right, Optimize Storage sets the Download Attachments menu to either Recent or None.

Empty Trash Automatically: From the Finder, choose Finder > Preferences, then click Advanced. Empty Trash Automatically selects “Remove items from the Trash after 30 days.”

Other ways that macOS helps automatically save space

With macOS Sierra or later, your Mac automatically takes these additional steps to save storage space:

• Detects duplicate downloads in Safari, keeping only the most recent version of the download
• Reminds you to delete used app installers
• Removes old fonts, languages, and dictionaries that aren't being used
• Clears caches, logs, and other unnecessary data when storage space is needed

How to free up storage space manually

Even without using the Optimized Storage features of Sierra or later, you can take other steps to make more storage space available:

• Music, movies, and other media can use a lot of storage space. Learn how to delete music, movies, and TV shows from your device.
• Delete other files that you no longer need by moving them to the Trash, then emptying the Trash. The Downloads folder is good place to look for files that you might no longer need.
• Move files to an external storage device.
• Compress files.
• Delete unneeded email: In the Mail app, choose Mailbox > Erase Junk Mail. If you no longer need the email in your Trash mailbox, choose Mailbox > Erase Deleted Items.

Learn more

• The Storage pane of About This Mac is the best way to determine the amount of storage space available on your Mac. Disk Utility and other apps might show storage categories such as Not Mounted, VM, Recovery, Other Volumes, Free, or Purgeable. Don't rely on these categories to understand how to free up storage space or how much storage space is available for your data.
• When you duplicate a file on an APFS-formatted volume, that file doesn't use additional storage space on the volume. Deleting a duplicate file frees up only the space required by any data you might have added to the duplicate. If you no longer need any copies of the file, you can recover all of the storage space by deleting both the duplicate and the original file.
• If you're using a pro app and Optimize Mac Storage, learn how to make sure that your projects are always on your Mac and able to access their files.

Choose your iMac model

If you're not sure which iMac you have, you can identify your iMac and then select it from the list below.

27-inch

24-inch

21.5-inch

• iMac (Retina 4K, 21.5-inch, 2019)*
• iMac (Retina 4K, 21.5-inch, 2017)*
• iMac (21.5-inch, 2017)*
• iMac (21.5 inch, Mid 2014)*
• iMac (21.5-inch, Late 2013)*
• iMac (21.5-inch, Late 2012)*

20-inch

17-inch

* Memory is not removable by users on iMac (21.5-inch, Late 2012), iMac (21.5-inch, Late 2013), iMac (21.5-inch, Mid 2014), iMac (21.5-inch, 2017), iMac (Retina 4K, 21.5-inch, 2017), and iMac (Retina 4K, 21.5-inch, 2019). If the memory in one of these computers needs repair service, contact an Apple Retail Store or Apple Authorized Service Provider. If you’d like to upgrade the memory in one of these models, an Apple Authorized Service Provider can help. Before you schedule an appointment, confirm that the specific Apple Authorized Service Provider offers memory upgrade services.

Memory in iMac (21.5-inch, Late 2015), and iMac (Retina 4K, 21.5-inch, Late 2015) is not upgradeable.

iMac (Retina 5K, 27-inch, 2020)

Get memory specifications for iMac (Retina 5K, 27-inch, 2020), then learn how to install memory in this model.

Memory specifications

This iMac model features Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

For optimal memory performance, DIMMs should be the same capacity, speed, and vendor. Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

• PC4-21333
• Unbuffered
• Nonparity
• 260-pin
• 2666MHz DDR4 SDRAM

If you have mixed capacity DIMMs, see the install memory section for installation recommendations.

iMac (Retina 5K, 27-inch, 2019)

Get memory specifications for iMac (Retina 5K, 27-inch, 2019), then learn how to install memory in this model.

Memory specifications

This iMac model features Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

• PC4-21333
• Unbuffered
• Nonparity
• 260-pin
• 2666MHz DDR4 SDRAM

iMac (Retina 5K, 27-inch, 2017)

Get memory specifications for iMac (Retina 5K, 27-inch, 2017), then learn how to install memory in this model.

Memory specifications

Apple Memory For Macbook Pro

This iMac model features Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

• PC4-2400 (19200)
• Unbuffered
• Nonparity
• 260-pin
• 2400MHz DDR4 SDRAM

iMac (Retina 5K, 27-inch, Late 2015)

Get memory specifications for iMac (Retina 5K, 27-inch, Late 2015), then learn how to install memory in this model.

Memory specifications

This iMac model features Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

• PC3-14900
• Unbuffered
• Nonparity
• 204-pin
• 1867MHz DDR3 SDRAM

For these 27-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

• iMac (Retina 5K, 27-inch, Mid 2015)
• iMac (Retina 5K, 27-inch, Late 2014)
• iMac (27-inch, Late 2013)
• iMac (27-inch, Late 2012)

Memory specifications

These iMac models feature Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

• PC3-12800
• Unbuffered
• Nonparity
• 204-pin
• 1600MHz DDR3 SDRAM

Installing memory

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After you shut down your iMac and give it time to cool, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Open the memory compartment door by pressing the small grey button located just above the AC power port:
5. The memory compartment door will open as the button is pushed in. Remove the compartment door and set it aside:
6. A diagram on the underside of the compartment door shows the memory cage levers and the orientation of the DIMM. Locate the two levers on the right and left sides of the memory cage. Push the two levers outward to release the memory cage:
7. After the memory cage is released, pull the memory cage levers toward you, allowing access to each DIMM slot.
8. Remove a DIMM by pulling the module straight up and out. Note the location of the notch on the bottom of the DIMM. When reinstalling DIMMs, the notch must be oriented correctly or the DIMM won't fully insert:
9. Replace or install a DIMM by setting it down into the slot and pressing firmly until you feel the DIMM click into the slot. When you insert a DIMM, make sure to align the notch on the DIMM to the DIMM slot. Find your model below for specific installation instructions and notch locations:
   • iMac (Retina 5K, 27-inch, 2020) DIMMs have a notch on the bottom, slightly left of the middle. If your DIMMs are mixed in capacity, minimize the capacity difference between Channel A (slots 1 and 2) and Channel B (slots 3 and 4) when possible.
     
   • iMac (Retina 5K, 27-inch, 2019) DIMMs have a notch on the bottom, slightly left of the middle:
   • iMac (27-inch, Late 2012) and iMac (Retina 5K, 27-inch, 2017) DIMMs have a notch on the bottom left:
     
   • iMac (27-inch, Late 2013) and iMac (Retina 5K, 27-inch, Late 2014, Mid 2015, and Late 2015) DIMMs have a notch on the bottom right:
     
10. After you install all of your DIMMs, push both memory cage levers back into the housing until they lock into place:
    
11. Replace the memory compartment door. You don't need to press the compartment door release button when replacing the compartment door.
12. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.
    

Your iMac performs a memory initialization procedure when you first turn it on after upgrading memory or rearranging DIMMs. This process can take 30 seconds or more, and the display of your iMac remains dark until it's finished. Make sure to let the memory initialization complete.

For these 27-inch and 21.5-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

• iMac (27-inch, Mid 2011)
• iMac (21.5-inch, Mid 2011)
• iMac (27-inch, Mid 2010)
• iMac (21.5-inch, Mid 2010)
• iMac (27-inch, Late 2009)
• iMac (21.5-inch, Late 2009)

Memory specifications

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

i5 and i7 Quad Core iMac computers come with both top memory slots populated. These computers will not start up if only a single DIMM is installed in any bottom slot; these computers should operate normally with a single DIMM installed in any top slot.

Core Duo iMac computers should operate normally with a single DIMM installed in any slot, top or bottom. ('Top' and 'bottom' slots refer to the orientation of the slots in the pictures below. 'Top' refers to the slots closest to the display; 'bottom' refers to the slots closest to the stand.)

Installing memory

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After you shut down your iMac and give it time to cool, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Using a Philips screwdriver, remove the RAM access door in the bottom of your computer:
   
5. Remove the access door and set it aside.
6. Untuck the tab in the memory compartment. If you're replacing a memory module, gently pull the tab to eject any installed memory module:
   
7. Insert your new or replacement SO-DIMM into the empty slot, noting the orientation of the keyway of the SO-DIMM as shown below.
8. After you insert it, press the DIMM up into the slot. There should be a slight click when you seat the memory correctly:
   
9. Tuck the tabs above the memory DIMMs, and reinstall the memory access door:
   
10. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

For these 24-inch and 20-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

• iMac (24-inch, Early 2009)
• iMac (20-inch, Early 2009)
• iMac (24-inch, Early 2008)
• iMac (20-inch, Early 2008)
• iMac (24-inch Mid 2007)
• iMac (20-inch, Mid 2007)

Memory specifications

These iMac computers have two side-by-side Synchronous Dynamic Random-Access Memory (SDRAM) slots in the bottom of the computer.

The maximum amount of random-access memory (RAM) you can install in each computer is:

You can use a 1GB or 2GB RAM module in each slot for iMac (Mid 2007) and iMac (Early 2008). Use 1GB, 2GB, or 4GB modules in each slot for the iMac (Early 2009).

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

DIMMs with any of the following features aren't supported:

• Registers or buffers
• PLLs
• Error-correcting code (ECC)
• Parity
• Extended data out (EDO) RAM

Installing memory

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After your iMac cools down, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Using a Philips screwdriver, remove the RAM access door in the bottom of the computer:
   
5. Remove the access door and set it aside.
6. Untuck the tab in the memory compartment. If you're replacing a memory module, untuck the tab and pull it to eject any installed memory module:
   
7. Insert your new or replacement RAM SO-DIMM into the empty slot, noting the orientation of the keyway of the SO-DIMM as shown above.
8. After you insert it, press the DIMM up into the slot. There should be a slight click when you seat the memory correctly.
9. Tuck the tabs above the memory DIMMs, and reinstall the memory access door:
   
10. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

For these 20-inch and 17-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

• iMac (20-inch Late 2006)
• iMac (17-inch, Late 2006 CD)
• iMac (17-inch, Late 2006)
• iMac (17-inch, Mid 2006)
• iMac (20-inch, Early 2006)
• iMac (17-inch, Early 2006)

Memory specifications

For best performance, fill both memory slots, installing an equal memory module in each slot.
*iMac (Late 2006) uses a maximum of 3 GB of RAM.

Installing memory in the bottom slot

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After you shut down your iMac and give it time to cool, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Using a Phillips screwdriver, remove the RAM access door on the bottom of the iMac and set it aside:
   
5. Move the DIMM ejector clips to their fully open position:
   
6. Insert your RAM SO-DIMM into the bottom slot, keeping in mind the orientation of the keyed SO-DIMM:
   
7. After you insert it, press the DIMM up into the slot with your thumbs. Don't use the DIMM ejector clips to push in the DIMM, as this might damage the SDRAM DIMM. There should be a slight click when you seat the memory fully.
8. Close the ejector clips:
   
9. Reinstall the memory access door:
   
10. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

Replacing memory in the top slot

After you shut down your iMac and give it time to cool, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Using a Phillips screwdriver, remove the RAM access door on the bottom of the iMac and set it aside:
   
5. Pull the two levers on each side of the memory compartment to eject the memory module that's already installed:
   
6. Remove the memory module from your iMac as shown below:
   
7. Insert your RAM SO-DIMM into the top slot, noting the orientation of the keyed SO-DIMM:
   
8. After you insert it, press the DIMM up into the slot with your thumbs. Don't use the DIMM ejector clips to push in the DIMM, as this might damage the SDRAM DIMM. There should be a slight click when you seat the memory fully.
9. Close the ejector clips:
   
10. Reinstall the memory access door:
    
11. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

If your iMac makes a tone after you install memory

iMac models introduced before 2017 might make a warning sound when you start up after installing or replacing memory:

• One tone, repeating every five seconds signals that no RAM is installed.
• Three successive tones, then a five-second pause (repeating) signals that RAM doesn't pass a data integrity check.

If you hear these tones, confirm that the memory you installed is compatible with your iMac and that it's installed correctly by reseating the memory. If your Mac continues to make the tone, contact Apple Support.

Confirm that your iMac recognizes its new memory

After you install memory, you should confirm that your iMac recognizes the new RAM by choosing Apple () menu > About This Mac.

The window that appears lists the total memory, including the amount of memory that originally came with the computer plus the newly added memory. If all the memory in the iMac has been replaced, it lists the new total of all installed RAM.

For detailed information about the memory installed in your iMac, click System Report. Then choose Memory under the Hardware section in the left side of System Information.

Apple Ram Mac Mini

If your computer doesn't recognize the memory or doesn't start up correctly, confirm that the RAM you installed is compatible with your iMac and that it's installed correctly by reseating the memory. If you continue to have issues with the memory in your iMac, contact Apple Support.