Apple iMac (21.5-inch, Late 2015) vs Apple iMac 24″ (M3)

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iMac (21.5-inch, Late 2015) compared with iMac 24″ (M3)

	AppleiMac (21.5-inch, Late 2015)	AppleiMac 24″ (M3)
Overview
Released
Released	October 2015	November 2023
Performance
Processor
Processor	Intel Core i5-5250U or Intel Core i5-5575R	Apple M3
CPU cores
CPU cores	2 or 4	8
Graphics
Graphics	Intel HD Graphics 6000 or Intel Iris Pro Graphics 6200	8-core GPU or 10-core GPU
Memory
Memory	8 GB or 16 GB	8 GB or 24 GB (better)
Storage
Storage	256 GB to 2 TB	256 GB to 2 TB
CPU
CPU	1.6 GHz dual-core Core i5 with Turbo Boost up to 2.7 GHz or 2.8 GHz quad-core Core i5 with Turbo Boost up to 3.3 GHz; Geekbench identifies the processors as Core i5-5250U and Core i5-5575R, respectively	8-core CPU with 4 performance cores and 4 efficiency cores
GPU
GPU	Intel HD Graphics 6000 in the 1.6 GHz model and Intel Iris Pro Graphics 6200 in the 2.8 GHz model; no discrete graphics option	8-core GPU (two-port model) or 10-core GPU (four-port models); hardware-accelerated ray tracing
AI engine
AI engine	–	16-core Neural Engine
Memory bandwidth
Memory bandwidth	–	100GB/s
Memory type
Memory type	8 GB of 1867 MHz LPDDR3 onboard memory, configurable to 16 GB; soldered memory cannot be upgraded after purchase (Expert Reviews and Alphr)	–
Storage type
Storage type	1 TB 5400-rpm hard drive on both models; the 1.6 GHz model can have a 1 TB Fusion Drive or 256 GB SSD, and the 2.8 GHz model can have a 1 TB or 2 TB Fusion Drive or 256 GB SSD. Apple specifies 24 GB of flash for the 1 TB Fusion Drive and 128 GB for the 2 TB Fusion Drive.	SSD
Media engine
Media engine	–	Hardware-accelerated H.264, HEVC, ProRes and ProRes RAW; video decode engine; video encode engine; ProRes encode and decode engine; AV1 decode
Display
Screen size
Screen size	21.5″	24″
Resolution
Resolution	1920 × 1080	4480 × 2520 (better)
Panel
Panel	IPS LCD	IPS LCD
Refresh rate
Refresh rate	–	60 Hz
Brightness
Brightness	–	500 nits
Display type
Display type	21.5-inch LED-backlit display with IPS technology; 1920 × 1080 with support for millions of colours. This is the non-Retina model.	4.5K Retina display; actual diagonal 23.5 inches
Pixel density
Pixel density	–	218 ppi
Display features
Display features	–	1 billion colours; wide colour (P3); True Tone
Connections
Ports
Ports	2 × Thunderbolt 2, 4 × USB-A, SD card slot, Ethernet, headphone jack	2 × USB4, headphone jack
Ethernet
Ethernet	1 Gb/s	–
External displays
External displays	Up to 1	Up to 1
Wi-Fi
Wi-Fi	802.11ac	Wi-Fi 6E
Bluetooth
Bluetooth	4.0	5.3
Camera
Camera	FaceTime HD	1080p FaceTime HD
Back ports
Back ports	Four USB 3 ports, two Thunderbolt 2 ports with Mini DisplayPort output, SDXC card slot, Gigabit Ethernet, headphone and optical digital audio output; Kensington lock slot. HDMI, DVI, VGA and dual-link DVI need separately sold adapters.	Two-port model: 2 × Thunderbolt / USB 4 with DisplayPort, Thunderbolt 3 (up to 40Gb/s), USB 4 (up to 40Gb/s) and USB 3.1 Gen 2 (up to 10Gb/s), Gigabit Ethernet optional; four-port models add 2 × USB 3 (up to 10Gb/s) and Gigabit Ethernet as standard; 3.5 mm headphone jack with advanced support for high-impedance headphones
External displays
External displays	Built-in display at native resolution alongside one external display up to 3840 × 2160 on the 1.6 GHz model or 4096 × 2304 on the 2.8 GHz model; extended desktop and video mirroring	One at up to 6K 60Hz
Camera
Camera	–	1080p FaceTime HD camera; advanced image signal processor with computational video
Speakers
Speakers	Stereo speakers; supports Apple iPhone headset with microphone	High-fidelity six-speaker system with force-cancelling woofers; wide stereo sound; Spatial Audio with Dolby Atmos
Microphones
Microphones	Dual microphones	Studio-quality three-mic array with high signal-to-noise ratio and directional beamforming
Keyboard and mouse
Keyboard and mouse	Magic Keyboard, Magic Mouse 2 and Lightning to USB cable; optional Magic Trackpad 2	Magic Keyboard (two-port model) or Magic Keyboard with Touch ID (four-port models), and Magic Mouse; Magic Trackpad or Magic Keyboard with Touch ID and Numeric Keypad available instead
Design and power
Type
Type	All-in-one	All-in-one
Weight
Weight	5.68 kg	4.43 kg (better)
Width × depth × height
Width × depth × height	528 × 175 × 450 mm	547 × 147 × 461 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. A built-in VESA mount version was available, but its listed height in inches conflicts with the metric value and is omitted.	–
Power supply
Power supply	100–240 V AC, 50–60 Hz, single phase	143W external power adapter; power lead (2 m)
Colours
Colours	–	Two-port model: Blue, Green, Pink, Silver; four-port models also Yellow, Orange, Purple
Noise
Noise	Apple reports operator-position sound pressure of 11.5 dB at idle and during wireless web, and 12 dB during hard-drive seek, tested on the 1.6 GHz Core i5 with 8 GB memory and 1 TB hard drive	–
Materials
Materials	Recyclable aluminium enclosure; arsenic-free display glass and mercury-free LED backlight; speaker enclosures contain 35 percent post-consumer recycled plastic	–
In the box
In the box	iMac, Magic Keyboard, Magic Mouse 2, Lightning to USB cable and power lead; OS X El Capitan at launch. The support sheet's macOS Sierra wording reflects a later software update.	iMac, Magic Keyboard (with Touch ID on four-port models), Magic Mouse, 143W power adapter, power lead (2 m), USB-C to Lightning Cable