Apple iMac Pro (2017) vs Apple iMac (Retina 4K, 21.5-inch, Late 2015)

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iMac Pro (2017) compared with iMac (Retina 4K, 21.5-inch, Late 2015)

	AppleiMac Pro (2017)	AppleiMac (Retina 4K, 21.5-inch, Late 2015)
Overview
Released
Released	December 2017	October 2015
Performance
Processor
Processor	Intel Xeon W-2140B, Intel Xeon W-2150B, Intel Xeon W-2170B or Intel Xeon W-2191B	Intel Core i5-5675R or Intel Core i7-5775R
CPU cores
CPU cores	8, 10, 14 or 18	4
Graphics
Graphics	Radeon Pro Vega 56 (8 GB HBM2), Radeon Pro Vega 64 (16 GB HBM2) or Radeon Pro Vega 64X (16 GB HBM2)	Intel Iris Pro Graphics 6200
Memory
Memory	32 GB, 64 GB, 128 GB or 256 GB (better)	8 GB or 16 GB
Storage
Storage	1 TB to 4 TB (better)	256 GB to 2 TB
CPU
CPU	Xeon W at 3.2 GHz with 8 cores (Turbo Boost 4.2 GHz), 3.0 GHz with 10 cores (4.5 GHz), 2.5 GHz with 14 cores (4.3 GHz) or 2.3 GHz with 18 cores (4.3 GHz). Exact W-B CPU identities follow Geekbench. The 8/10-core versions launched first; Macworld reports later January 2018 availability for 14/18-core options. Apple changed the standard configuration to 10 cores in August 2020.	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
GPU
GPU	Radeon Pro Vega 56 with 8 GB HBM2, optionally Vega 64 or Vega 64X with 16 GB HBM2. Vega 64X is a later option included in Apple’s current specification sheet, absent from the launch reviews.	–
Memory type
Memory type	Quad-channel 2666 MHz DDR4 ECC; 32 GB standard, configurable to 64/128/256 GB. The current maker sheet includes the later 256 GB option; launch reviews cover up to 128 GB. No user-accessible memory door.	1867 MHz LPDDR3 onboard memory; 8 GB standard, configurable to 16 GB at purchase
Storage type
Storage type	1 TB SSD, configurable to 2 or 4 TB	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.
Display
Screen size
Screen size	27″	21.5″
Resolution
Resolution	5120 × 2880 (better)	4096 × 2304
Panel
Panel	IPS LCD	IPS LCD
Brightness
Brightness	500 nits	–
Display type
Display type	LED-backlit Retina 5K display; IPS panel confirmed by EveryMac. Native refresh rate omitted because Apple does not publish it in the specification sheet.	LED-backlit Retina 4K display with IPS technology and support for millions of colours
Display features
Display features	Wide colour (P3); supports one billion colours	P3 colour gamut; Apple does not publish brightness or refresh rate in this model's specification sheet
Connections
Ports
Ports	4 × Thunderbolt 3, 4 × USB-A, SD card slot, Ethernet, headphone jack	2 × Thunderbolt 2, 4 × USB-A, SD card slot, Ethernet, headphone jack
Ethernet
Ethernet	10 Gb/s (better)	1 Gb/s
External displays
External displays	Up to 4 (better)	Up to 1
Wi-Fi
Wi-Fi	802.11ac	802.11ac
Bluetooth
Bluetooth	5.0	4.0
Camera
Camera	1080p FaceTime HD	FaceTime HD
Back ports
Back ports	Four USB-A ports; four Thunderbolt 3 USB-C ports with DisplayPort 1.2, Thunderbolt up to 40 Gb/s and USB 3.1 Gen 2 up to 10 Gb/s; UHS-II SDXC, Nbase-T Ethernet supporting 1/2.5/5/10Gb and 3.5 mm headphone jack. Thunderbolt 2, HDMI, DVI and VGA require 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	Two 5120 × 2880 displays at 60 Hz with one billion colours, four 3840 × 2160 displays at 60 Hz with one billion colours, or four 4096 × 2304 displays at 60 Hz with millions of colours, alongside the built-in display	Built-in display at full native resolution alongside one external display up to 4096 × 2304; extended desktop and video mirroring
Speakers
Speakers	Stereo speakers	Stereo speakers; supports Apple iPhone headset with microphone
Microphones
Microphones	Four microphones; supports Hey Siri	Dual microphones
Keyboard and mouse
Keyboard and mouse	Space grey Magic Keyboard with Numeric Keypad and Magic Mouse 2; optional space grey Magic Trackpad 2	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	9.7 kg	5.68 kg (better)
Width × depth × height
Width × depth × height	650 × 203 × 516 mm	528 × 175 × 450 mm
Operating system
Operating system	macOS	macOS
Size and weight detail
Size and weight detail	Dimensions include the stand; weight varies by configuration and manufacturing process. Optional VESA mount adapter kit.	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
Materials
Materials	Recyclable aluminium enclosure; arsenic-free glass and mercury-free LED backlight	Recyclable aluminium enclosure; arsenic-free display glass; mercury-free LED backlight
In the box
In the box	iMac Pro, space grey Magic Keyboard with Numeric Keypad, space grey Magic Mouse 2, Lightning to USB cable and power lead	iMac, Magic Keyboard, Magic Mouse 2, power lead and Lightning to USB cable