Apple iMac with Retina 5K Display (mid-2015) review: More affordable, but beware expensive upgrades

  • Editors' rating
    8.5 Excellent


  • Outstanding 5K Retina display
  • Competitive price
  • Slimline, all-in-one design
  • Good external connectivity


  • No internal drive bays or upgrade slots
  • Limited user upgrade or repair options
  • Apple's BTO upgrades are expensive

The revamped 27-inch iMac that Apple launched towards the end of 2014 was tailor-made for high-end video-editing work. It was relatively expensive, of course, with a starting price of £1,999 (inc. VAT; £1,665.83 ex. VAT), yet that price was justified by the unrivalled clarity and 5,120-by-2,880-pixel resolution of its 5K Retina display, as well as workstation levels of performance for tasks such as 4K video-editing.

However, many of Apple's most loyal users work in fields such as photography and publishing, which can benefit from a high-resolution display but may not require quite the same amount of raw horsepower. With that in mind, Apple has now released a second iMac model with the same 5K Retina display, but slightly lower performance and more affordable pricing.


The new 5K iMac has a slightly lower spec than the original model, and costs £250 less.

Images: Apple

Retina options

The new iMac With Retina 5K Display starts at £1,599 (inc. VAT; £1,332.5 ex. VAT), a price that allows it to replace the previous top-end non-Retina iMac. The base model includes a quad-core Core i5 processor running at 3.3GHz (3.7GHz with Turbo Boost), along with 8GB of RAM, a 1TB hard drive and discrete AMD Radeon R9 M290 graphics with 2GB of dedicated video memory.

At the same time, the original high-end Retina model that was introduced last year has now been reduced to £1,849 (inc. VAT; £1,541 ex. VAT) and runs at 3.5GHz, with 8GB of RAM, a 1TB hybrid HD/SSD and Radeon R9 M290X graphics. In contrast, Dell charges £2,002 (inc. VAT; £1,668 ex. VAT) for its standalone UltraSharp 27 Ultra HD 5K monitor, so £1,599 for the combination of a 5K monitor and a quad-core graphics workstation is pretty competitive.


The 5K iMac has four USB 3.0 ports and two Thunderbolt ports, plus Gigabit Ethernet and headphone connectors and an SDXC card slot.

Image: Apple

However, the same can't be said of Apple's build-to-order upgrade options, which include £160 (inc. VAT; £133 ex. VAT) for just another 8GB of RAM, and the same again to upgrade to a 1TB hybrid drive. Thankfully, the 27-inch iMac is one of the few Apple products that still allows user upgrades for the memory. The iMac's lack of expansion slots means that there are no other user upgrade options available, but its complement of four USB 3.0 ports and two high-performance Thunderbolt 2.0 ports does make it easy to add extra storage when required.


There's not much difference in performance between the two iMac models either. The 3.3GHz processor in our review unit achieved a score of 11,804 for multi-core performance when running Geekbench 3, as opposed to 12,500 for its 3.5GHz counterpart. Graphics performance is close too, with the 3.3GHz iMac achieving 88.1fps for OpenGL performance, compared to 91.9fps for the 3.5GHz model. There are dedicated graphics workstations -- including Apple's own Mac Pro -- that provide stronger performance, but there's really nothing in this price range that can match the iMac's combination of performance and high-quality 5K display.


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In recent years, Apple has been criticised for focusing on consumer products such as the iPhone and the new Apple Watch. However, the 5K iMac is very much aimed at Apple's traditional creative users, and provides an unrivalled combination of 5K display and strong performance. Video editors may prefer to squeeze maximum power out of the more expensive 3.5GHz model, but this new, more affordable version of the iMac with Retina 5K Display will be an ideal tool for graphic design and photography.


Product Form Factor All-in-one
Packaged Quantity 1
Built-in Devices 2 microphones, stereo speakers
Processor / Chipset
CPU Intel Core i5 (4th Gen) 3.3 GHz
Max Turbo Speed 3.7 GHz
Number of Cores Quad-Core
Processor Main Features Intel Turbo Boost Technology 2
Cache Memory
Installed Size L3 cache - 6 MB
Cache Per Processor 6 MB
Type L3 cache
Per Processor Size 6 MB
Installed Size 6 MB
Installed Size 8 GB / 32 GB (max)
Technology DDR3 SDRAM
Memory Speed 1600 MHz
Configuration Features 2 x 4 GB
Technology DDR3 SDRAM
Installed Size 8 GB
Max Supported Size 32 GB
Form Factor SO-DIMM 204-pin
Slots Qty 4
Empty Slots 2
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
Interface Type SATA
Spindle Speed 7200 rpm
Type HDD
Interface Class Serial ATA
Installed Qty 1
Capacity 1 TB
Type keyboard, mouse
Hard Drive (3rd)
Type none
Wireless Protocol 802.11a/b/g/n/ac, Bluetooth 4.0
Optical Storage
Drive Type no optical drive
Type none
Installed Qty 1
Max Supported Qty 1
Type Core i5
Generation 4
Manufacturer Intel
Clock Speed 3.3 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
Packaged Quantity 1
Compatibility Mac
Data Link Protocol Bluetooth 4.0, Ethernet, Fast Ethernet, Gigabit Ethernet, IEEE 802.11a, IEEE 802.11ac, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n
Compliant Standards Bluetooth 4.0, 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
Security Slot Type Kensington security slot
Type personal computer
Hard Drive Capacity 1 TB
Introduced Mid 2015
Graphics Controller
Graphics Processor AMD Radeon R9 M290
Video Memory 2 GB GDDR5 SDRAM
Dimensions & Weight
Width 25.6 in
Depth 8 in
Height 20.3 in
Form Factor all-in-one
Manufacturer Form Factor all-in-one
Built-in Devices 2 microphones, stereo speakers
Manufacturer Warranty
Type 1 year warranty
Audio Output
Sound Output Mode stereo
Type none
Keyboard Name Apple Wireless Keyboard
Connectivity wireless
Interface Bluetooth
Environmental Standards
ENERGY STAR Certified Yes
Expansion / Connectivity
Slots 4 (total) / 2 (free) x SO-DIMM 204-pin
Mouse Name Apple Magic Mouse
Connectivity wireless
Technology laser
Interface Bluetooth
Features Multi-Touch
Physical Characteristics
Form Factor all-in-one
Weight 21.03 lbs
Type power supply
Min Operating Temperature 50 °F
Max Operating Temperature 95 °F
Operating System / Software
OS Provided: Type Apple macOS 10.12 Sierra
OS Provided Apple macOS Sierra 10.12
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 R9 M290
Graphics Processor Series AMD Radeon R9
Video Memory
Technology GDDR5 SDRAM
Installed Size 2 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