Apple iMac (Retina 4K, 21.5-inch, Late 2015) vs Apple iMac (Retina 5K, 27-inch, Late 2015)

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iMac (Retina 4K, 21.5-inch, Late 2015) compared with iMac (Retina 5K, 27-inch, Late 2015)

	AppleiMac (Retina 4K, 21.5-inch, Late 2015)	AppleiMac (Retina 5K, 27-inch, Late 2015)
Overview
Released
Released	October 2015	October 2015
Performance
Processor
Processor	Intel Core i5-5675R or Intel Core i7-5775R	Intel Core i5-6500, Intel Core i7-6700K or Intel Core i5-6600
CPU cores
CPU cores	4	4
CPU threads
CPU threads	–	4 or 8
Graphics
Graphics	Intel Iris Pro Graphics 6200	AMD Radeon R9 M380 (2 GB GDDR5), AMD Radeon R9 M390 (2 GB GDDR5), AMD Radeon R9 M395 (2 GB GDDR5) or AMD Radeon R9 M395X (4 GB GDDR5)
Memory
Memory	8 GB or 16 GB	8 GB, 16 GB or 32 GB (better)
Storage
Storage	256 GB to 2 TB	256 GB to 3 TB (better)
CPU
CPU	3.1 GHz quad-core Core i5 with Turbo Boost up to 3.6 GHz; configurable to 3.3 GHz quad-core Core i7 with Turbo Boost up to 3.8 GHz	3.2 GHz quad-core Core i5 with Turbo Boost up to 3.6 GHz in the M380 and M390 models; 3.3 GHz quad-core Core i5 with Turbo Boost up to 3.9 GHz in the M395 model. Only the M390 and M395 bases support the 4.0 GHz Core i7 upgrade, with Turbo Boost up to 4.2 GHz.
GPU
GPU	–	AMD Radeon R9 M380 or M390 with 2 GB GDDR5; M395 with 2 GB GDDR5 in the upper base, configurable to M395X with 4 GB GDDR5 only in that base
Memory type
Memory type	1867 MHz LPDDR3 onboard memory; 8 GB standard, configurable to 16 GB at purchase	1867 MHz DDR3; 8 GB standard as two 4 GB modules, configurable to 16 GB or 32 GB; four user-accessible SO-DIMM slots
Storage type
Storage type	1 TB 5400-rpm hard drive; optional 1 TB or 2 TB Fusion Drive, or 256 GB or 512 GB SSD. The 1 TB Fusion Drive combines a hard drive with 24 GB of flash; the 2 TB version has 128 GB of flash.	M380 base: 1 TB 7200-rpm hard drive, 1/2/3 TB Fusion Drive or 256/512 GB SSD. M390 base: 1/2/3 TB Fusion Drive or 256/512 GB/1 TB SSD. M395 base: 2/3 TB Fusion Drive or 256/512 GB/1 TB SSD. The 1 TB Fusion Drive has 24 GB of flash; 2/3 TB Fusion Drives have 128 GB.
Display
Screen size
Screen size	21.5″	27″
Resolution
Resolution	4096 × 2304	5120 × 2880 (better)
Panel
Panel	IPS LCD	IPS LCD
Display type
Display type	LED-backlit Retina 4K display with IPS technology and support for millions of colours	LED-backlit Retina 5K display with IPS technology and support for millions of colours
Display features
Display features	P3 colour gamut; Apple does not publish brightness or refresh rate in this model's specification sheet	P3 colour gamut; Apple does not publish brightness or refresh rate in this model's specification sheet
Connections
Ports
Ports	2 × Thunderbolt 2, 4 × USB-A, SD card slot, Ethernet, headphone jack	2 × Thunderbolt 2, 4 × USB-A, SD card slot, Ethernet, headphone jack
Ethernet
Ethernet	1 Gb/s	1 Gb/s
External displays
External displays	Up to 1	Up to 2 (better)
Wi-Fi
Wi-Fi	802.11ac	802.11ac
Bluetooth
Bluetooth	4.0	4.0
Camera
Camera	FaceTime HD	FaceTime HD
Back ports
Back ports	Four USB 3 ports, two Thunderbolt 2 ports with Mini DisplayPort output, SDXC card slot, Gigabit Ethernet, 3.5 mm headphone and optical digital audio output; Kensington lock slot. HDMI, DVI, VGA and dual-link DVI require separately sold adapters.	Four USB 3 ports, two Thunderbolt 2 ports with Mini DisplayPort output, SDXC card slot, Gigabit Ethernet, 3.5 mm headphone and optical digital audio output; Kensington lock slot. HDMI, DVI, VGA and dual-link DVI require separately sold adapters.
External displays
External displays	Built-in display at full native resolution alongside one external display up to 4096 × 2304; extended desktop and video mirroring	Built-in display at full native resolution alongside up to two 4096 × 2160 displays, or one 5120 × 2880 dual-cable display; extended desktop and video mirroring
Speakers
Speakers	Stereo speakers; supports Apple iPhone headset with microphone	Stereo speakers; supports Apple iPhone headset with microphone
Microphones
Microphones	Dual microphones	Dual microphones
Keyboard and mouse
Keyboard and mouse	Rechargeable Magic Keyboard and Magic Mouse 2; optional Magic Trackpad 2 with Force Touch	Rechargeable Magic Keyboard and Magic Mouse 2; optional Magic Trackpad 2 with Force Touch
Design and power
Type
Type	All-in-one	All-in-one
Weight
Weight	5.68 kg (better)	9.54 kg
Width × depth × height
Width × depth × height	528 × 175 × 450 mm	650 × 203 × 516 mm
Operating system
Operating system	macOS	macOS
Size and weight detail
Size and weight detail	Dimensions include the stand; weight varies by configuration. A built-in VESA mount version was also available.	Dimensions include the stand; weight varies by configuration. A built-in VESA mount version was also available.
Power supply
Power supply	100–240 V AC, 50–60 Hz, single phase	100–240 V AC, 50–60 Hz, single phase
Noise
Noise	Apple's 3.1 GHz Core i5, 8 GB, 1 TB hard-drive test configuration: operator-position sound pressure 11 dB at idle and wireless web, 11.5 dB during hard-drive seek	Apple's 3.3 GHz Core i5, 8 GB, 2 TB Fusion Drive and Radeon M395 test configuration: operator-position sound pressure 15.5 dB at idle, wireless web and hard-drive seek
Materials
Materials	Recyclable aluminium enclosure; arsenic-free display glass; mercury-free LED backlight	Recyclable aluminium enclosure; arsenic-free display glass; mercury-free LED backlight
In the box
In the box	iMac, Magic Keyboard, Magic Mouse 2, power lead and Lightning to USB cable	iMac, Magic Keyboard, Magic Mouse 2, power lead and Lightning to USB cable