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Apple iMac 27-inch with Retina 5K display (2017): CPU and GPU upgrades deliver better value for money

  • Editors' rating
    9.0 Outstanding


  • 7th generation Kaby Lake CPU
  • Improved GPU
  • Brighter display
  • Two Thunderbolt 3 ports


  • Poor upgradeability
  • Only 8GB of RAM as standard
  • Expensive build-to-order options

When the iMac was first launched, it was very much intended as an affordable home computer -- and, indeed, was often derided for its cute, candy-coloured design. In recent years, though, the iMac has gradually evolved into a professional-level graphics workstation, and that status has now been confirmed with Apple's recent announcement of the forthcoming iMac Pro.

However, the iMac Pro isn't due until December, and Apple's recent admission that it got things wrong with the cylindrical design of the Mac Pro means that the company now has a gaping hole in its desktop line-up. And so, rather than simply opting for a mid-year Kaby Lake speed-bump, Apple has given the iMac a more thorough make-over, and effectively promoted it to the role of flagship desktop system for creative and professional users.


As well as internal upgrades, the 2017 5K iMac offers a brighter 500-nit display.

Images: Apple

Turning Pro

Superficially, the 2017 version of the 27-inch iMac doesn't look all that different. On the inside, though, virtually all the main components have been updated: Faster solid-state drives, up to 64GB of DDR4 RAM, more powerful GPUs, faster Thunderbolt 3 connectivity, and, of course, Intel's seventh-generation Kaby Lake processors. Even the keyboard has been updated for professional users, with the addition of a numeric keypad and larger set of navigation keys.

Unfortunately, the new keyboard is an optional extra costing £30 ($30), rather than a standard feature. Thankfully, though, the updated 2017 iMac does provide better value for money, and helps to compensate for the Brexit-related price bump that added around 20 percent across Apple's entire UK product range toward the end of last year.

As always, the iMac is available in three standard configurations, with the entry-level model reviewed here retaining last year's £1,749 (inc. VAT) price tag (£1,457.50 ex. VAT, or $1,799). That price now includes a new quad-core Core i5-7500 processor running at 3.4GHz (up to 3.8GHz with TurboBoost), 8GB of DDR4 RAM, and a 1TB hybrid Fusion drive.

There's been a big graphics upgrade, too, in a belated attempt to get a foot in the door with the VR crowd. So, as well as increasing the brightness of the iMac's 5K Retina Display to 500 nits (matching that of the MacBook Pro), Apple has also opted for a more powerful Radeon Pro 570 GPU with 4GB of VRAM.

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The other two standard configurations also keep last year's pricing: £1,949 inc. VAT (£1,624.17 ex. VAT, or $1,999) for a 3.5GHz Core i5 CPU and a Radeon Pro 575 GPU; and £2,249 inc. VAT (£1,874.17 ex. VAT, or $2,299) for the top-end configuration with a 3.8GHz Core i5, a 2TB Fusion drive, and an 8GB Radeon Pro 580 GPU.


The 2017 iMac's connections are: 3.5mm headphone jack, SD card slot, four USB 3 ports, two Thunderbolt 3/USB-C ports, Gigabit Ethernet (RJ-45), Kensington lock slot.

Image: Apple

Virtual Value

It's no surprise to see a speed-bump from the new Intel processor, but Apple's recognition of the need to woo the VR community with a substantial graphics upgrade means that this year's entry-level model now provides the same level of performance as the previous top-of-the-range configuration from 2016.

Geekbench 4.1 reports CPU scores of 4,845 and 14,000 for single- and multi-core performance respectively, while the 2017 iMac also hits 99.5fps per second for graphics performance under Cinebench R15. You'd have had to pay £2,249 for that sort of performance last year -- 4,897 and 13,387 for Geekbench and 94.5fps for Cinebench to be precise -- so this year's iMac certainly provides better value for money than its predecessors.

In contrast, a rival all-in-one Windows system such as Dell's XPS 27 starts at £1,699 with a 4K display, but only has a 2.7GHz Skylake processor, a conventional 1TB hard drive, and relies on integrated graphics. We're still irritated by the iMac's standard 8GB of memory, which is inadequate for a professional-level system and clearly intended to lure you into purchasing some of Apple's expensive build-to-order options. And, as ever, user upgrades are limited to just the memory alone -- although, surprisingly, there are reports that the new 21.5-inch version of the iMac actually allows CPU upgrades for those brave enough to dismantle the all-in-one display panel. But limited upgradeability is a weakness shared by most AIO systems, and the 27-inch iMac remains a rare example of an Apple product that can actually outgun its Windows PC rivals in terms of both performance and value for money.


Image: Apple


Necessity, as the saying goes, is the mother of invention. With the Mac Pro range effectively put on hold, Apple has acknowledged that it needed to give the iMac a substantial performance boost in order to provide the performance that its professional and creative users need -- especially if it hopes to compete in emerging fields such as VR. Some iMac owners may be tempted to wait for the forthcoming iMac Pro, but this 2017 update proves that the veteran iMac is still alive and kicking.

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Product Form Factor All-in-one
Packaged Quantity 1
Built-in Devices microphone, stereo speakers
Processor / Chipset
CPU Intel Core i5 (7th Gen)
Max Turbo Speed 4.2 GHz
Number of Cores Quad-Core
Processor Main Features Intel Turbo Boost Technology 2
Max Supported Size 64 GB
Form Factor SO-DIMM 260-pin
Slots Qty 4
Empty Slots 2
Memory Speed 2400 MHz
Configuration Features 2 x 4 GB
Technology DDR4 SDRAM
Installed Size 8 GB
Environmental Parameters
Humidity Range Operating 5 - 95% (non-condensing)
Min Operating Temperature 50 °F
Max Operating Temperature 95 °F
Widescreen Display Yes
Monitor Features LED-backlit
Type LED
TFT Technology IPS
Diagonal Size (metric) 68.6 cm
Display Resolution Abbreviation 5K
Hard Drive
Capacity 1 x 2 TB
Interface Type SATA
Features Fusion Drive
Type Hybrid Drive
Interface Class Serial ATA
Installed Qty 1
Capacity 2 TB
Type keyboard, mouse
Localization & Layout English
Wireless Protocol 802.11a/b/g/n/ac, Bluetooth 4.2
Optical Storage
Drive Type no optical drive
Type none
Installed Qty 1
Max Supported Qty 1
Type Core i5
Generation 7
Manufacturer Intel
Clock Speed 3.8 GHz
Card Reader
Type card reader
Supported Flash Memory Cards SD Memory Card, SDHC Memory Card, SDXC Memory Card
Storage Removable
Type none
Brand Apple
Product Line Apple iMac
Model with Retina 5K display
Localization English
Country Kits United States
Packaged Quantity 1
Compatibility Mac
Data Link Protocol Bluetooth 4.2, Ethernet, Fast Ethernet, Gigabit Ethernet, IEEE 802.11a, IEEE 802.11ac, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n
Compliant Standards Bluetooth 4.2, IEEE 802.11a, IEEE 802.11ac, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n
Wireless LAN Supported Yes
Monitor Type LED - IPS
Native Resolution 5120 x 2880 (5K)
Diagonal Size 27 in
Image Brightness 500 cd/m2
Security Slot Type Kensington security slot
Type personal computer
Hard Drive Capacity 2 TB
Introduced Mid 2017
Form Factor all-in-one
Manufacturer Form Factor all-in-one
Built-in Devices microphone, stereo speakers
Graphics Controller
Graphics Processor AMD Radeon Pro 580
Video Memory 8 GB
Dimensions & Weight
Width 25.6 in
Depth 8 in
Height 20.3 in
Manufacturer Warranty
Type 1 year warranty
Audio Output
Sound Output Mode stereo
Keyboard Name Apple Magic Keyboard
Connectivity wireless
Interface Bluetooth
Type none
Environmental Standards
ENERGY STAR Certified Yes
Audio Input
Type Microphone
Mouse Name Apple Magic Mouse 2
Connectivity wireless
Technology laser
Interface Bluetooth
Features Multi-Touch
Physical Characteristics
Form Factor all-in-one
Weight 20.81 lbs
Type power supply
Voltage Required AC 100-240 V
Min Operating Temperature 50 °F
Max Operating Temperature 95 °F
Operating System / Software
OS Provided Apple macOS Catalina 10.15
Type App Store, Apple AirDrop, Apple AirPlay, Apple Dashboard, Apple FaceTime, Apple GarageBand, Apple Keynote, Apple Mac OS X Mail, Apple Mission Control, Apple Numbers, Apple Pages, Apple Preview, Apple Safari, Apple Spotlight, Apple Time Machine, Apple iBooks, Apple iMovie, Apple iPhoto, Apple iTunes, Calendar, Contacts, Dictation, Facebook, Family Sharing, Game Center, Maps, Messages, Notes, Notification Center, Photo Booth, Power Saver, Reminders, Twitter, iCloud
Video Output
Graphics Processor AMD Radeon Pro 580
Graphics Processor Series AMD Radeon Pro
Video Memory
Installed Size 8 GB
Service & Support
Type 1 year warranty
Service & Support Details
Type limited warranty, technical support
Service Included phone consulting
Full Contract Period 1 year, 90 days