Apple iMac (21.5-inch, 2017) vs Apple iMac (Retina 5K, 27-inch, 2019)

Every spec side by side, from each maker's published figures.

Better figure, where one is clearly better

iMac (21.5-inch, 2017) compared with iMac (Retina 5K, 27-inch, 2019)
AppleiMac (21.5-inch, 2017)AppleiMac (Retina 5K, 27-inch, 2019)
Overview
ReleasedJune 2017March 2019
Performance
ProcessorIntel Core i5-7360UIntel Core i5-8500, Intel Core i5-8600, Intel Core i9-9900K or Intel Core i5-9600K
CPU cores26 or 8
CPU threads46 or 16
GraphicsIntel Iris Plus Graphics 640Radeon Pro 570X (4 GB GDDR5), Radeon Pro 575X (4 GB GDDR5), Radeon Pro 580X (8 GB GDDR5) or Radeon Pro Vega 48 (8 GB HBM2)
Memory8 GB or 16 GB8 GB, 16 GB, 32 GB or 64 GB (better)
Storage256 GB to 1 TB256 GB to 3 TB (better)
CPU2.3 GHz dual-core Intel Core i5 with Turbo Boost up to 3.6 GHz; Geekbench identifies the exact processor as Core i5-7360USix-core Core i5 at 3.0 GHz (Turbo Boost 4.1 GHz), 3.1 GHz (Turbo Boost 4.3 GHz) or 3.7 GHz (Turbo Boost 4.6 GHz); upper two bases configurable to 3.6 GHz eight-core Core i9 with Turbo Boost up to 5.0 GHz. Exact K-suffix CPU identities follow Geekbench’s model database; Macworld instead lists KF suffixes.
GPUIntel Iris Plus Graphics 640; no discrete graphics optionRadeon Pro 570X or 575X with 4 GB GDDR5, or Radeon Pro 580X with 8 GB GDDR5; only the upper base supports Radeon Pro Vega 48 with 8 GB HBM2
Memory type8 GB of 2133 MHz DDR4, configurable to 16 GB2666 MHz DDR4; 8 GB standard as two 4 GB modules in four user-accessible SO-DIMM slots. Lower base configurable to 16/32 GB; upper two bases to 16/32/64 GB.
Storage type1 TB 5400-rpm hard drive, configurable to 1 TB Fusion Drive or 256 GB SSD570X base: 1/2 TB Fusion Drive or 256/512 GB/1 TB SSD. 575X base: 1/2/3 TB Fusion Drive or 256/512 GB/1 TB SSD. 580X/Vega base: 2/3 TB Fusion Drive or 512 GB/1/2 TB SSD.
Display
Screen size21.5″27″
Resolution1920 × 10805120 × 2880 (better)
Panel–IPS LCD
Brightness–500 nits
Display type21.5-inch LED-backlit display; 1920 × 1080 with support for millions of colours. Apple does not identify the panel technology, native refresh rate or brightness in its specification sheet; Retina model display figures do not apply.LED-backlit Retina 5K display; IPS panel confirmed by EveryMac; Apple does not publish native refresh rate in this model’s specification sheet
Display features–Wide colour (P3); supports one billion colours
Connections
Ports2 × Thunderbolt 3, 4 × USB-A, SD card slot, Ethernet, headphone jack2 × Thunderbolt 3, 4 × USB-A, SD card slot, Ethernet, headphone jack
Ethernet1 Gb/s1 Gb/s
External displaysUp to 2Up to 2
Wi-Fi802.11ac802.11ac
Bluetooth4.24.2
CameraFaceTime HDFaceTime HD
Back portsFour USB-A ports, two Thunderbolt 3 (USB-C) ports, SDXC card slot, Gigabit Ethernet, 3.5 mm headphone jack and Kensington lock slot. Thunderbolt 3 supports DisplayPort, up to 40 Gb/s Thunderbolt and up to 10 Gb/s USB 3.1 Gen 2; Thunderbolt 2, HDMI, DVI and VGA require adapters.Four USB-A ports; two Thunderbolt 3 USB-C ports with DisplayPort, Thunderbolt up to 40 Gb/s and USB 3.1 Gen 2 up to 10 Gb/s; SDXC, Gigabit Ethernet and 3.5 mm headphone jack; Kensington lock slot. Thunderbolt 2, HDMI, DVI and VGA require separately sold adapters.
External displaysBuilt-in display at native resolution alongside one 5120 × 2880 display at 60 Hz with one billion colours, two 3840 × 2160 displays at 60 Hz with one billion colours, or two 4096 × 2304 displays at 60 Hz with millions of coloursBuilt-in display at full native resolution alongside one 5120 × 2880 display at 60 Hz with one billion colours, two 3840 × 2160 displays at 60 Hz with one billion colours, or two 4096 × 2304 displays at 60 Hz with millions of colours
SpeakersStereo speakers; supports Apple iPhone headset with microphoneStereo speakers
MicrophonesBuilt-in microphoneBuilt-in microphone
Keyboard and mouseMagic Keyboard, Magic Mouse, Lightning to USB cable and polishing cloth; configurable with Magic Keyboard with Numeric Keypad or Magic TrackpadRechargeable Magic Keyboard and Magic Mouse 2; optional Magic Keyboard with Numeric Keypad and Magic Trackpad 2
Design and power
TypeAll-in-oneAll-in-one
Weight5.44 kg (better)9.42 kg
Width × depth × height528 × 175 × 450 mm650 × 203 × 516 mm
Operating systemmacOSmacOS
Size and weight detailDimensions include the stand; weight varies by configuration and manufacturing process. A built-in VESA mount version was available.Dimensions include the stand; weight varies by configuration. A built-in VESA mount version was also available.
Power supply100–240 V AC, 50–60 Hz, single phase100–240 V AC, 50–60 Hz, single phase
NoiseApple reports operator-position sound pressure of 11 dB at idle and during wireless web, and 12 dB during hard-drive seek, tested on the Core i5 with 8 GB memory and 1 TB hard drive–
MaterialsAluminium enclosure; arsenic-free display glass; mercury-, BFR- and beryllium-free with regional exceptions for PVC-free power leadsRecyclable aluminium enclosure; arsenic-free glass and mercury-free LED backlight
In the boxiMac, Magic Keyboard, Magic Mouse, Lightning to USB cable, polishing cloth and power lead. Apple's current support page describes the later macOS Big Sur release.iMac, Magic Keyboard, Magic Mouse 2, power lead and Lightning to USB cable

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