Updated with 4K Retina display option on 21.5-inch, all-Retina 27-inch lineup


At a Glance

  • Apple's iMac is an ultra-thin all-in-one desktop computer, available in 21.5- and 27-inch sizes with an array of build-to-order upgrades. The iMac family was updated on October 13, 2015 to an all-Retina lineup for the 27-inch models, while the 21.5-inch lineup received its first 4K Retina display as a high-end option.

27-inch Retina iMac

  • 5120 x 2880 Retina display
  • Up to 4.0 GHz Skylake processor option
  • AMD discrete graphics
  • Pricing starts at $1799

21.5-inch iMac

  • 4096 x 2304 Retina display option
  • Up to 3.3 GHz Broadwell processor option
  • Intel Iris Pro 6200 integrated graphics on most models
  • Pricing starts at $1099, or $1499 for Retina

This page is current as of 6 weeks ago
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What's New

On October 13, 2015, Apple refreshed its entire iMac lineup, introducing Skylake chips and AMD graphics for the 5K Retina 27-inch models and adding Broadwell chips and a 4K Retina display to the 21.5-inch iMac line. None of the iMacs received external design changes and continue to offer the same "ultra-thin" slim-bodied design and fully laminated display that was introduced in 2012, but there have been some significant internal changes.


Apple has eliminated all non-Retina 27-inch iMac models, with each of the 27-inch iMacs now offering next-generation quad-core Skylake processors, AMD Radeon graphics, and 5120 x 2880 5K Retina displays. The 27-inch iMac is available in three base configurations.

The entry-level model, available for $1,799, includes a 3.2GHz processor with 8GB RAM and a 1TB 7,200 RPM hard drive. The mid-level model, priced at $1,999, has the same 3.2GHz processor and 8GB RAM, but it ships with a faster 1TB Fusion Drive. The high-end model includes a 3.3GHz processor, 8GB RAM, and a 2TB Fusion Drive.

Apple's 21.5-inch iMac lineup continues to feature lower-cost standard non-Retina models, which are being sold alongside the new high-end 21.5-inch iMac that comes with a 4K Retina display. All of the iMacs include integrated graphics and Broadwell processors rather than Skylake processors.

At the low end, the $1,099 iMac includes the same 1.6GHz dual-core Broadwell processor that's used in the MacBook Air. It ships with a 1TB 5,400 RPM hard drive, 8GB RAM, Intel HD Graphics 6000, and continues to offer a 1920 x 1080 display. The $1,299 mid-level iMac includes the same 1920 x 1080 display, but offers a more powerful quad-core 2.8GHz Broadwell processor, Iris Pro Graphics 6200, 8GB RAM, and a 1TB hard drive.


The high-end 21.5-inch iMac includes a 4096 x 2304 Retina display, along with a quad-core 3.1GHz Broadwell processor, 8GB RAM, Iris Pro Graphics 6200, and a 1TB hard drive.

Most mid and high-level 21.5 and 27-inch iMac models can be upgraded with faster processors, while all models have build-to-order options that include Fusion Drives or flash storage and additional RAM. All iMacs include two Thunderbolt 2 ports and four USB 3 ports. They support 802.11ac Wi-Fi and include Bluetooth 4.0.


Apple's iMac lineup ships with a new Apple Magic Keyboard and an Apple Magic Mouse 2 or an Apple Magic Trackpad 2, all of which were also updated on October 13, 2015. The three new accessories include minor design changes, Lightning ports, and rechargeable batteries, with the Apple Magic Trackpad 2 gaining Force Touch capabilities.

21.5-inch iMacs

The major addition to the 21.5-inch iMac line is the high-end model that now includes a 4K Retina display to complement the 5K Retina iMac that's been around since 2014. Apple is selling the 4K iMac alongside two lower-priced non-Retina models, and all three models have been updated with faster Broadwell processors and integrated Intel graphics.


There are no longer discrete graphics options for the 21.5-inch iMac models, even at the high end, and all models ship with a 1TB hard drive as a base option and 8GB RAM.

Design wise, the 21.5-inch iMac continues to look like the previous-generation iMac, with an ultra thin 5mm thick laminated display. It measures in at 17.7 inches by 20.8 inches and weighs 12.5 pounds.

Available Models

  • $1,099 - 1920 x 1080 sRGB display, 1.6GHz dual-core Core i5 processor, 8GB RAM, 1TB hard drive, Intel HD Graphics 6000.
  • $1,299 - 1920 x 1080 sRGB display, 2.8GHz quad-core Core i5 processor, 8GB RAM, 1TB hard drive, Intel Iris Pro Graphics 6200.
  • $1,499 - 4K 4096 x 2304 P3 display, 3.1GHz quad-core Core i5 processor, 8GB RAM, 1TB hard drive, Intel Iris Pro Graphics 6200.

Build-to-Order Upgrade Options

The low-end and mid-range non-Retina 21.5-inch iMacs can be upgraded with a maximum of 16GB RAM for an additional $200 and a 1TB Fusion Drive for $100 or 256GB Flash Storage for $200. The mid-range model can also be upgraded with a 2TB Fusion Drive for an additional $300. The processors in these machines cannot be upgraded.

The 21.5-inch 4K Retina iMac can be upgraded with a quad-core 3.3GHz Intel Core i7 processor for $200, and up to 16GB RAM for another $200. There are also several storage options:

  • 1TB Fusion Drive - $100
  • 2TB Fusion Drive - $300
  • 256GB Flash Storage - $200
  • 512GB Flash Storage - $500

Apple's PCIe-based flash storage options are the top choice for performance for both the 21.5-inch and 27-inch iMac. According to Apple, the flash storage is 2.5 times faster than the previous version, offering up to 1800MB/s of sequential read performance. Upgrading to a Fusion drive in the new machines post purchase won't be easy due to the removal of an extra PCIe SSD slot that was in the previous-generation iMac, so customers interested in high-speed storage should opt for a Fusion drive or flash storage when ordering.

Customers purchasing a 21.5-inch iMac should buy the maximum amount of RAM to ensure the machine's longevity. The memory in the 21.5-inch machines is soldered in, so it is not user upgradeable.

CPU Performance

Benchmarks of the mid-range and high-end 21.5-inch iMacs suggest they offer a decent performance improvement over previous-generation machines. The new 21.5-inch iMacs use Intel's Broadwell chips, while the 2013 iMacs used Haswell chips.

Using Geekbench, the 21.5-inch 4K Retina iMac scored 3,787 on the single-core 64-bit test and 12,803 on the multi-core test. The comparable late 2013 2.9GHz iMac had a single core score of 3,543 and a multi-core score of 10,685.


The mid-range non-Retina 21.5-inch iMac with a 2.8GHz quad-core processor got a single-core score of 3,532 and a multi-core score of 11,865. The comparable mid-range late 2013 iMac with a 2.7GHz processor scored 3,175 on the single-core test and 10,199 on the multi-core test.

The 21.5-inch 4K Retina iMac can be up upgraded with a 3.3GHz quad-core Core i7 processor and shows even better performance gains than the two stock models.


The 4096 x 2304 resolution display includes 9.4 million pixels, which is 4.5 times more than the standard 1920 x 1080 display of the rest of the 21.5-inch iMac lineup.


In addition to a 4K resolution, the new display features a wider P3-based color gamut that offers a 25 percent larger color space for more available colors to make images more vivid and detailed than ever before. Unlike with a typical sRGB display, the P3 color gamut in the Retina iMac uses red-green phosphor LEDs instead of standard white LEDs to better represent red, green, and blue.

According to Apple, with 25 percent more available colors on the display, color will appear as it does in real life.

Hard Drive Controversy

Each of the base model 21.5-inch iMacs ships with a 5,400 RPM 1TB Serial ATA hard drive, a surprising choice due to the hard drive's slow speed compared to other components within the machines. Many iMac buyers will likely want to spend extra money to upgrade to flash storage or a Fusion Drive that pairs flash storage with a standard hard drive, both of which will be significantly faster than the standard hard drive option.

To keep prices lower, the 1TB Fusion Drive option includes a 1TB hard drive paired with a 24GB SSD. Earlier iMac models included a 1TB hard drive with a 128GB SSD. 128GB of storage for the Fusion Drive is now limited to the 2TB Fusion Drive options.

27-inch iMacs

Apple's 2015 iMac update eliminates all non-Retina 27-inch iMacs. All 27-inch iMacs now ship with Skylake processors, AMD Radeon graphics, and a 5K Retina display. All of the models continue to carry the same external design, measuring in at 20.3 inches by 25.6 inches and weighing 21 pounds. The display itself is just 5mm thick with a 1.4mm display panel.


Available Models

  • $1,799 - Retina 5K 5120 x 2880 P3 display, 3.2GHz quad-core Intel Core i5 processor, 8GB RAM, 1TB hard drive, AMD Radeon R9 M380 with 2GB video memory.
  • $1,999 - Retina 5K 5120 x 2880 P3 display, 3.2GHz quad-core Intel Core i5 processor, 8GB RAM, 1TB Fusion Drive, AMD Radeon R9 M390 with 2GB video memory.
  • $2,299 - Retina 5K 5120 x 2880 P3 display, 3.3GHz quad-core Intel Core i5 processor, 8GB RAM, 2TB Fusion Drive, AMD Radeon R9 M395 with 2GB video memory.

The 27-inch Retina iMac ships with a standard 7,200 RPM hard drive at the low end, which is the slowest piece of hardware in the machine. It's also worth noting that the 1TB Fusion Drive in the iMac includes a 1TB hard drive paired with a 24GB SSD, while the 2TB Fusion Drive includes a 2TB hard drive paired with a 128GB SSD.

Build-to-Order Upgrade Options

There are no processor upgrade options for the entry-level 3.2GHz iMac, but both the mid-range 3.2GHz and high-end 3.2GHz models can be upgraded with a 4.0GHz quad-core Intel Core i7 processor for $250. The high-end 27-inch iMac can be upgraded with an AMD Radeon M395X graphics card with 4GB video memory.

All models of the 27-inch iMac can be upgraded with additional memory. 16GB is available for $200 and 32GB is available for $600. The following storage upgrade options are available:

  • Entry-level - 1TB Fusion Drive, $100; 2TB Fusion Drive, $300; 3TB Fusion Drive, $400; 256GB Flash Storage, $200; 512GB Flash Storage, $500.
  • Mid-range - 2TB Fusion Drive, $200; 3TB Fusion Drive, $300; 256GB Flash Storage, $100; 512GB Flash Storage, $400; 1TB Flash Storage, $900.
  • High-end - 256GB Flash Storage, no cost; 3TB Fusion Drive, $100; 512GB Flash Storage, $200; 1TB Flash Storage, $700.

Apple's PCIe-based flash storage options are the top choice for performance for both the 21.5-inch and 27-inch iMac. According to Apple, the flash storage is 2.5 times faster than the previous version, offering up to 1800MB/s of sequential read performance.

The 27-inch Skylake iMacs support up to 64GB of memory, with a 16GB module in each slot. Apple offers a maximum of 32GB RAM, but users can add 48 or 64GB using third-party options.

CPU Performance

While the 21.5-inch iMac uses Broadwell chips, the 27-inch iMac has the latest and greatest current-generation Skylake chips. Compared to the previous-generation 27-inch iMacs that used a mix of Haswell and Broadwell chips, the Skylake chips bring solid improvements.

In a Geekbench 3 test, the 3.2GHz chip used in the entry-level and mid-range 27-inch iMacs earned a single core score of 3,931 and a multi-core score of 12,079. That's a significant improvement over the comparable late 2014 5K 27-inch iMac, which saw single-core scores of 3,339 and multi-core scores of 10,632.

The high-end 27-inch iMac with a 3.3GHz processor scored 4,214 on the single-core test and 13,081 on the multi-core test, while the comparable mid-2015 5K iMac with a 3.5GHz Broadwell processor scored 3,844 on the single-core test and 12,192 on the multi-core test.


The mid-range and high-end 27-inch iMacs can be upgraded with a 4.0GHz quad-core Core i7 processor, which shows even greater performance improvements over previous-generation models.


Like the 4K 21.5-inch iMac, the 5K Retina iMacs include a display with a wider P3 color gamut that expands the range of available colors to add more detail and life to images on the screen. The display of the 5K Retina iMac has 14.7 million pixels.


It uses red-green phosphor LEDs instead of white LEDs to better represent red, green, and blue for more accurate real-world color.

AMD Radeon Graphics

The 21.5-inch iMac uses integrated graphics, but the 27-inch models include new AMD high-performance graphics. According to Apple, the graphics give the 27-inch iMac up to 3.7 teraflops of graphics compute power.

All default 27-inch iMac models ship with AMD Radeon cards that have 2GB video memory, but the high-end model can be upgraded with an AMD Radeon M395X with 4GB video memory, which may be a worthwhile upgrade for those who plan to do system intensive gaming or photo/video editing.

Other iMac Features

All of the iMacs in Apple's lineup include a FaceTime HD video camera, stereo speakers, and dual microphones. They include Bluetooth 4.0 support and super fast 802.11ac Wi-Fi, which has been included in all iMacs and MacBooks for the last few years.

With 802.11ac, wireless performance is three times faster than with 802.11n. 802.11ac supports a theoretical transfer rate of 1.3 gigabits per second, a huge improvement over the 450 megabits per second of 802.11n.


Rear ports on the machines include a 3.5mm headphone jack, an SDXC card slot, four USB 3.0 ports, two Thunderbolt 2 ports, and a Gigabit Ethernet port.

iMac Accessories

Apple's new iMacs ship with a Magic Mouse 2 and a Magic Keyboard, but the Magic Mouse 2 can be swapped for a Magic Trackpad 2 for an additional $50. Separately, the Magic Keyboard is priced at $99, the Magic Trackpad 2 is priced at $129, and the Magic Mouse 2 is priced at $79.

All new Magic accessories can only be used with Macs running OS X 10.11 El Capitan, and the new Magic Trackpad 2 requires a Bluetooth 4.0-enabled Mac.

Magic Mouse 2

Apple's second-generation Magic Mouse includes a new design that eliminates the need for traditional batteries and reduces the number of moving parts inside the mouse. Rather than using standard batteries, it includes a rechargeable lithium ion battery that can be charged using a standard Lightning to USB cable.


The new Magic Mouse is lighter because of its redesigned internals, and it has a continuous bottom shell and an optimized foot design that lets it track easier and move with less resistance on a desk or table.

It takes approximately two hours to charge the Magic Mouse 2 to full, but it includes a fast charge feature that provides nine hours of battery life in two minutes. The Magic Mouse is the only one of the new Magic accessories that cannot be used while it's charging because its Lightning port is on the bottom of the device.

Magic Trackpad 2

Apple's Magic Trackpad 2 features an edge-to-edge glass surface that's 30 percent larger than the original Magic Trackpad and for the first time, it brings Force Touch to the iMac. There are four force sensors underneath the Magic Trackpad's surface, letting it detect the amount of pressure applied to the surface.

Force Touch on the iMac enables a range of new gestures in apps like Mail and Safari. Force clicking text within a webpage or Mail message brings up results like dictionary definitions and more, while force clicking on an address will give a Maps preview. A force click on a flight number brings up details on the flight, and a force click on a link brings up a website preview.


There are dozens of similar capabilities for Force Touch, and several third-party apps have also introduced support for the feature as it's previously been available on Apple's Retina MacBook Pro and 12-inch MacBook machines.

The Magic Trackpad 2 includes a built-in battery and it charges via Lightning port using a Lightning to USB cable.

Magic Keyboard

The new Magic Keyboard is an updated version of the Apple Wireless Keyboard. It's been redesigned to incorporate a built-in rechargeable battery and a Lightning port that's used to charge the battery. It includes a revamped scissor mechanism underneath the keys for improved stability and better travel with a slimmer design.


According to Apple, the battery in the Magic Keyboard will power it for about a month between charges, and it can be used while it's being charged via a Lightning to USB cable.


Reviews for the new 21.5 and 27-inch iMacs have been largely positive, with a lot of praise for the Retina displays with wider color gamut, but there's also been criticism of the slow 5400 RPM hard drive the 21.5 and entry-level 27-inch iMacs ship with and the lack of a USB-C port and support for Thunderbolt 3.

Ars Technica's Andrew Cunningham was a fan of the display of the 4K and 5K iMacs and their quad-core processor, but would have preferred to see Thunderbolt 3 or USB Type-C ports instead of Thunderbolt 2.

Then there are the frustrating choices Apple has made across the lineup: No Thunderbolt 3 or USB Type-C even though those technologies are apparently ready to go, and no standard Fusion Drive or SSD in any but the top-end 27-inch iMacs. At $100, the jump to a Fusion Drive (albeit a smaller one than in years past) is cheaper than ever, but Apple could really afford to stick that 24GB drive inside every single one of these iMacs to alleviate the unmitigated misery that is using a 5400RPM hard drive in a $1500 desktop computer in this the year of our Lord 2015.

CNET's Dan Ackerman said the new 21.5-inch iMac isn't a must-have upgrade, but thought it competitively priced. He recommends existing iMac users pick up the new Magic Keyboard and Magic Mouse or Magic Trackpad.

For everyone else, even if you don't regularly view 4K content, a sharp-looking Retina-level display is one of those things that's nearly impossible to give up once you get used to it, and the new 4K iMac is competitively priced with the handful of 4K-display Windows PCs we've reviewed.

Engadget's Dana Wollman said the new iMac "mostly hits the right notes" but criticized the lack of discrete graphics in the 4K Retina iMac and the lack of Fusion Drives in lower-priced models.

The iMac is still the best all-in-one, with an attractive (if predictable) design, near-standard 4K and 5K screens, and even better color accuracy than before. The 21.5-inch version is in some ways the more interesting of the two models, as this is the first time the smaller Mac has been offered with a Retina display. [...]

As you can see, then, the iMac mostly hits the right notes, although I wish Apple were more generous with the other specs -- besides display quality and resolution, that is. The 21.5-inch version is no longer offered with discrete graphics, not even on the 4K edition, which seems like a mistake. Meanwhile, hybrid Fusion drives only come standard on machines priced from $1,999.

Macworld's Jason Snell wasn't a fan of the slow 5400 RPM hard drive in the new iMac.

The base storage configuration of the 4K iMac is a 1TB, 5400rpm hard drive. It's been a few years since I regularly used a Mac with a spinning disk as its primary hard drive, and man, did it feel slow. Starting up was slow. Launching apps was slow. Everything... just... took... longer. It's disconcerting to take a brand-new, top-of-its-line Mac out of the box and be disappointed by how sluggish it feels, but that's what I experienced, and it's pretty much down to that slow hard drive.

Finally, The Wall Street Journal's Jeffrey Fowler praised the new iMac's screen, calling reds and greens in particular brighter and more vibrant, but noted many images can't take advantage of the DCI-P3 format the new iMacs support.

When you look at these new iMac screens, reds and greens in particular look brighter or more vibrant, like somebody cranked up the saturation dial to 11. With 25% more colors to work with, there's also more detail because the monitors aren't eliminating certain hues.

With an old and new iMac side by side, I could spot the difference on some photos, but not all. One problem is that many of our photos--including ones taken with the latest iPhone 6s--are saved in a reduced color palette called sRGB. To take advantage of the new screens, you need images or video saved in a format called DCI-P3. (Not coincidentally, the Mac's Photos app can now save to that format, but you'll have to start with high-quality images, like from a DSLR.)

How to Buy

The new 21.5 and 27-inch iMacs are available from the Apple online store and from Apple retail locations. In the United States, orders ship out within 24 hours of being placed and should deliver within just a few days.

iMacs with build-to-order options take longer to prepare and will not ship out for a week to a week and a half, depending on the shipping option chosen.

What's Next

Apple's future chip plans for the iMac are difficult to decipher. Intel does not intend to release desktop class socketed Skylake chips with integrated Iris or Iris Pro graphics that would be appropriate for the lower-end iMacs that currently use integrated graphics.

With no prospective chips available for the lower-end iMacs, it is not clear what Apple is going to do in terms of processor upgrades, making it nearly impossible to predict when we might see the next iMac update or what it might include. Intel plans to release Kaby Lake processors in late 2016, but details on Kaby Lake chips appropriate for the iMac are not available, and it's possible Kaby Lake could see delays.

AMD and NVIDIA are introducing new GPU products in 2016, which could perhaps make their way into future Apple Macs. AMD is planning to unveil GPUs based on Global Foundries' 14 nm FinFET processor node, while NVIDIA will introduce GPUs based on TSMC's 16 nm FinFET Plus processor node, both bringing significant improvements in graphics performance.

AMD has reportedly won a contract with Apple to supply the discrete graphics chips for future high-end 27-inch iMac and 15-inch Retina MacBook Pros. Performance of the new graphics chips is expected to be double that of their predecessors, measured on a per-watt basis.

AMD plans to introduce the new GPUs ahead of the back-to-school shopping season, but it is not clear if the technology will be ready in time for or used in Apple's 2016 iMac update. If Apple launches new iMacs late in the year, there's a possibility that they could include the new GPUs from AMD. Discrete graphics cards are only available in the 27-inch iMac, so this information applies only to those models. 21.5-inch iMacs use integrated graphics from Intel.

Best Prices
21.5-inch iMac (Late 2015): 1.6 GHz, 8 GB RAM, 1 TB
21.5-inch iMac (Late 2015): 2.8 GHz, 8 GB RAM, 1 TB
21.5-inch Retina iMac (Late 2015): 3.1 GHz, 8 GB RAM, 1 TB
27-inch Retina iMac (Late 2015): 3.2 GHz, 8 GB RAM, 1 TB
27-inch Retina iMac (Late 2015): 3.2 GHz, 8 GB RAM, 1 TB Fusion
27-inch Retina iMac (Late 2015): 3.3 GHz, 8 GB RAM, 2 TB Fusion

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