Skip to content
MacIQ

iMac (Retina 5K, 27-inch, 2017) vs iMac (Retina 5K, 27-inch, Late 2015)

iMac (Retina 5K, 27-inch, 2017)1iMac (Retina 5K, 27-inch, Late 2015)2

Quick look

Quick look: iMac (Retina 5K, 27-inch, 2017) against iMac (Retina 5K, 27-inch, Late 2015)
FigureiMac (Retina 5K, 27-inch, 2017)1iMac (Retina 5K, 27-inch, Late 2015)2
Price£1,7493launch price£1,4494launch price
ChipCore i53.4GHz quad-core IntelCore i53.2GHz quad-core Intel
CPU4-coreCPU4-coreCPU
Memory8GBmemory, base8GBmemory, base
Storage1TBstorage, base1TBstorage, base
Display27-inchdisplay27-inchdisplay
Released7 June 20175ReleasedIn Apple Stores; orderable online from 5 June 2017.13 October 20154Released
Security updates15 September 20256Security updates ended16 September 20246Security updates ended
Price
The iMac (Retina 5K, 27-inch, 2017) is £1,749 at launch, per Apple UK Store (archived 23 June 2017); the iMac (Retina 5K, 27-inch, Late 2015) is £1,449 at launch, per Apple Newsroom (UK).

True to scale

iMac (Retina 5K, 27-inch, 2017) · 650 × 516 mm frontiMac (Retina 5K, 27-inch, Late 2015) · 650 × 516 mm front

Front faces, from Apple’s published dimensions, drawn to one scale and superposed. Corner rounding is our drawing convention, not a measurement.

Specifications

Each figure is from the source marked by its Mac’s name unless it carries its own small number, which links to where that figure was read.

Body

Body: Apple iMac (Retina 5K, 27-inch, 2017) against Apple iMac (Retina 5K, 27-inch, Late 2015)
SpecificationiMac (Retina 5K, 27-inch, 2017)1iMac (Retina 5K, 27-inch, Late 2015)2
Dimensions516 x 650 x 203 mm516 x 650 x 203 mm
Weight9.44 kg9.54 kg
PortsTwo Thunderbolt 3 (USB-C) ports, four USB 3 ports, SDXC card slot, Gigabit Ethernet (RJ-45), 3.5 mm headphone jackTwo Thunderbolt 2 ports, four USB 3 ports, SDXC card slot, Gigabit Ethernet (RJ-45), 3.5 mm headphone jack
Thunderbolt ports722
Thunderbolt versionThunderbolt 3Thunderbolt 2
USB-A ports44
HDMINo HDMI port.8No HDMI port.9
SD card slotYesYes
Headphone jackYesYes
KeyboardMagic KeyboardMagic Keyboard
Touch IDNo Touch ID.8No Touch ID.9

Display

Display: Apple iMac (Retina 5K, 27-inch, 2017) against Apple iMac (Retina 5K, 27-inch, Late 2015)
SpecificationiMac (Retina 5K, 27-inch, 2017)1iMac (Retina 5K, 27-inch, Late 2015)2
Display size27 in27 in
Resolution5120 x 28805120 x 2880
Display typeRetina 5K displayRetina 5K display with IPS technology
Brightness500 nitsNot available10
Wide colour (P3)YesYes11

Chip and memory

Chip and memory: Apple iMac (Retina 5K, 27-inch, 2017) against Apple iMac (Retina 5K, 27-inch, Late 2015)
SpecificationiMac (Retina 5K, 27-inch, 2017)1iMac (Retina 5K, 27-inch, Late 2015)2
Chip3.4GHz quad-core Intel Core i53.2GHz quad-core Intel Core i5
Apple siliconIntel processor, not Apple silicon.12Intel processor, not Apple silicon.13
CPU cores44
GraphicsRadeon Pro 570 with 4GB of VRAMAMD Radeon R9 M380 with 2GB of GDDR5 memory
Chip options3.4GHz quad-core Intel Core i5, 3.5GHz quad-core Intel Core i5, 3.8GHz quad-core Intel Core i5, or 4.2GHz quad-core Intel Core i73.2GHz quad-core Intel Core i5, 3.3GHz quad-core Intel Core i5, or 4.0GHz quad-core Intel Core i7
Memory (base)8GB8GB
Memory (maximum)64GB32GB
Memory options8GB, 16GB, 32GB or 64GB8GB, 16GB or 32GB
Memory upgradeable by userYes, as Apple documents14Yes, as Apple documents14
Storage (base)1TB1TB
Storage (maximum)3TB3TB
Storage options1TB, 2TB or 3TB Fusion Drive, or 256GB, 512GB, 1TB or 2TB SSD1TB hard drive, 1TB, 2TB or 3TB Fusion Drive, or 256GB, 512GB or 1TB flash storage (SSD)

Connectivity

Connectivity: Apple iMac (Retina 5K, 27-inch, 2017) against Apple iMac (Retina 5K, 27-inch, Late 2015)
SpecificationiMac (Retina 5K, 27-inch, 2017)1iMac (Retina 5K, 27-inch, Late 2015)2
Wi-Fi802.11ac Wi-Fi802.11ac Wi-Fi
Bluetooth4.24.0
Ethernet10/100/1000BASE-T Gigabit Ethernet (RJ-45)10/100/1000BASE-T Gigabit Ethernet (RJ-45)
External displays (base)22

Camera and audio

Camera and audio: Apple iMac (Retina 5K, 27-inch, 2017) against Apple iMac (Retina 5K, 27-inch, Late 2015)
SpecificationiMac (Retina 5K, 27-inch, 2017)1iMac (Retina 5K, 27-inch, Late 2015)2
CameraFaceTime HD cameraFaceTime HD camera
SpeakersStereo speakersStereo speakers
MicrophonesMicrophoneDual microphones

Platform

Platform: Apple iMac (Retina 5K, 27-inch, 2017) against Apple iMac (Retina 5K, 27-inch, Late 2015)
SpecificationiMac (Retina 5K, 27-inch, 2017)1iMac (Retina 5K, 27-inch, Late 2015)2
Shipped withNot available15OS X El Capitan16
Newest macOSmacOS Ventura17macOS Monterey17
Model identifieriMac18,317iMac17,117
Model year20172015

Benchmarks

Benchmarks: Apple iMac (Retina 5K, 27-inch, 2017) against Apple iMac (Retina 5K, 27-inch, Late 2015)
SpecificationiMac (Retina 5K, 27-inch, 2017)1iMac (Retina 5K, 27-inch, Late 2015)2
Geekbench 7 (CPU, single-core)1,210181,08118
Geekbench 7 (CPU, multi-core)3,333182,90318

Sources

  1. Apple Support (UK) — iMac (Retina 5K, 27-inch, 2017) - Technical Specifications · Default for iMac (Retina 5K, 27-inch, 2017) · Apple’s figure · read 15 Sep 2026

    ↩

  2. Apple Support (UK) — iMac (Retina 5K, 27-inch, Late 2015) - Technical Specifications · Default for iMac (Retina 5K, 27-inch, Late 2015) · Apple’s figure · read 15 Sep 2026

    ↩

  3. Apple UK Store (archived 23 June 2017) — iMac Retina 5K 27-inch, 3.4GHz quad-core Core i5, 8GB, 1TB Fusion Drive, £1,749.00 · third-party figure · read 11 Oct 2026

    ↩

  4. Apple Newsroom (UK) — Apple Updates iMac Family with Stunning New Retina Displays · Apple’s figure · read 15 Sep 2026

    ↩

  5. Apple Newsroom (UK) — iMac receives major update featuring more powerful graphics, faster processors, Thunderbolt 3 and brighter displays · Apple’s figure · read 15 Sep 2026

    ↩

  6. endoflife.date — Apple macOS · third-party figure · read 2 Oct 2026

    ↩

  7. Different Thunderbolt generations. iMac (Retina 5K, 27-inch, 2017): Thunderbolt 3. iMac (Retina 5K, 27-inch, Late 2015): Thunderbolt 2.

    ↩

  8. iMac (Retina 5K, 27-inch, 2017): No HDMI port. No Touch ID. Checked: Apple Support (UK) — iMac (Retina 5K, 27-inch, 2017) - Technical Specifications. Read 9 Oct 2026

    ↩

  9. iMac (Retina 5K, 27-inch, Late 2015): No HDMI port. No Touch ID. Checked: Apple Support (UK) — iMac (Retina 5K, 27-inch, Late 2015) - Technical Specifications. Read 9 Oct 2026

    ↩

  10. Not published by Apple. Pages checked: Apple Support (UK) — iMac (Retina 5K, 27-inch, Late 2015) - Technical Specifications; Apple Support (UK) — Identify your iMac model; Apple Newsroom (UK) — Apple Updates iMac Family with Stunning New Retina Displays. Read 9 Oct 2026

    ↩

  11. Apple Newsroom (UK) — Apple Updates iMac Family with Stunning New Retina Displays · Apple’s figure · read 3 Oct 2026

    ↩

  12. iMac (Retina 5K, 27-inch, 2017): Intel processor, not Apple silicon. Checked: Apple Support (UK) — iMac (Retina 5K, 27-inch, 2017) - Technical Specifications. Read 15 Sep 2026

    ↩

  13. iMac (Retina 5K, 27-inch, Late 2015): Intel processor, not Apple silicon. Checked: Apple Support (UK) — iMac (Retina 5K, 27-inch, Late 2015) - Technical Specifications. Read 15 Sep 2026

    ↩

  14. Apple Support (UK) — Install memory in an iMac · Apple’s figure · read 18 Oct 2026

    ↩

  15. Not published by Apple. Pages checked: Apple Support (UK) — iMac (Retina 5K, 27-inch, 2017) - Technical Specifications; Apple Support (UK) — Identify your iMac model; Apple Newsroom (UK) — iMac receives major update featuring more powerful graphics, faster processors, Thunderbolt 3 and brighter displays. Read 9 Oct 2026

    ↩

  16. Apple Newsroom (UK) — Apple Updates iMac Family with Stunning New Retina Displays · Apple’s figure · read 9 Oct 2026

    ↩

  17. Apple Support (UK) — Identify your iMac model · Apple’s figure · read 15 Sep 2026

    ↩

  18. Geekbench Browser (Primate Labs) · third-party figure · read 11 Oct 2026

    ↩

Not published by Apple

iMac (Retina 5K, 27-inch, 2017). Apple doesn’t publish for this Mac: colours, pixel density, refresh rate, nano-texture option, GPU cores, storage upgradeable by user, maximum continuous power. Geekbench 7 Metal: the Mac chart has no Metal score for this Mac (chart read 10 Oct 2026). Pages checked: Apple Support (UK) — iMac (Retina 5K, 27-inch, 2017) - Technical Specifications; Apple Support (UK) — Identify your iMac model; Apple Newsroom (UK) — iMac receives major update featuring more powerful graphics, faster processors, Thunderbolt 3 and brighter displays, read 9 Oct 2026.

iMac (Retina 5K, 27-inch, Late 2015). Apple doesn’t publish for this Mac: colours, pixel density, refresh rate, nano-texture option, GPU cores, storage upgradeable by user, maximum continuous power. Geekbench 7 Metal: the Mac chart has no Metal score for this Mac (chart read 10 Oct 2026). Pages checked: Apple Support (UK) — iMac (Retina 5K, 27-inch, Late 2015) - Technical Specifications; Apple Support (UK) — Identify your iMac model; Apple Newsroom (UK) — Apple Updates iMac Family with Stunning New Retina Displays, read 9 Oct 2026.

If you own one of them

Whether to move is a different question from which is better. Each Mac has a page on it: what its successor changes (the newest Mac in its line where Apple sells one, otherwise the Mac this site treats as its replacement, which can be in another line), what it fetches and whether it still gets updates. Should I upgrade my iMac (Retina 5K, 27-inch, 2017)? · Should I upgrade my iMac (Retina 5K, 27-inch, Late 2015)?

The pairs a buyer of either Mac would also weigh. Any two Macs in the catalogue can be compared from the chooser.