Apple iMac 24″ (M4) vs Apple iMac (Retina 4K, 21.5-inch, Late 2015)

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iMac 24″ (M4) compared with iMac (Retina 4K, 21.5-inch, Late 2015)

	AppleiMac 24″ (M4)	AppleiMac (Retina 4K, 21.5-inch, Late 2015)
Overview
Released
Released	November 2024	October 2015
Performance
Processor
Processor	Apple M4	Intel Core i5-5675R or Intel Core i7-5775R
CPU cores
CPU cores	8 or 10	4
Graphics
Graphics	8-core GPU or 10-core GPU	Intel Iris Pro Graphics 6200
AI engine (NPU)
AI engine (NPU)	38 TOPS	–
Memory
Memory	16 GB, 24 GB or 32 GB (better)	8 GB or 16 GB
Storage
Storage	256 GB to 2 TB	256 GB to 2 TB
CPU
CPU	8-core CPU with 4 performance cores and 4 efficiency cores (two-port model), or 10-core CPU with 4 performance cores and 6 efficiency cores (four-port models)	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
Memory type
Memory type	–	1867 MHz LPDDR3 onboard memory; 8 GB standard, configurable to 16 GB at purchase
GPU
GPU	Hardware-accelerated ray tracing	–
AI engine
AI engine	16-core Neural Engine	–
Memory bandwidth
Memory bandwidth	120GB/s	–
Storage type
Storage type	SSD	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.
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	24″	21.5″
Resolution
Resolution	4480 × 2520 (better)	4096 × 2304
Panel
Panel	IPS LCD	IPS LCD
Refresh rate
Refresh rate	60 Hz	–
Brightness
Brightness	500 nits	–
Display type
Display type	4.5K Retina display; actual diagonal 23.5 inches	LED-backlit Retina 4K display with IPS technology and support for millions of colours
Pixel density
Pixel density	218 ppi	–
Display features
Display features	1 billion colours; wide colour (P3); True Tone; nano-texture glass option on four-port models	P3 colour gamut; Apple does not publish brightness or refresh rate in this model's specification sheet
Connections
Ports
Ports	2 × Thunderbolt 4, headphone jack	2 × Thunderbolt 2, 4 × USB-A, SD card slot, Ethernet, headphone jack
Ethernet
Ethernet	–	1 Gb/s
External displays
External displays	Up to 1	Up to 1
Wi-Fi
Wi-Fi	Wi-Fi 6E	802.11ac
Bluetooth
Bluetooth	5.3	4.0
Camera
Camera	12MP Center Stage	FaceTime HD
Back ports
Back ports	2 × Thunderbolt / USB 4 (two-port model) or 4 × Thunderbolt 4 (four-port models), each with Thunderbolt 4 and USB 4 (up to 40Gb/s), USB 3.1 Gen 2 (up to 10Gb/s) and DisplayPort; Gigabit Ethernet on the power adapter, standard on four-port models and optional on the two-port model	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-port model: one at up to 6K 60Hz; four-port models: two at up to 6K 60Hz, or one at up to 8K 60Hz	Built-in display at full native resolution alongside one external display up to 4096 × 2304; extended desktop and video mirroring
Camera
Camera	12MP Center Stage camera with Desk View; 1080p HD video recording; advanced image signal processor with computational video	–
Speakers
Speakers	High-fidelity six-speaker system with force-cancelling woofers; wide stereo sound; Spatial Audio with Dolby Atmos	Stereo speakers; supports Apple iPhone headset with microphone
Microphones
Microphones	Studio-quality three-mic array with high signal-to-noise ratio and directional beamforming	Dual microphones
Keyboard and mouse
Keyboard and mouse	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	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	4.42 kg (better)	5.68 kg
Width × depth × height
Width × depth × height	547 × 147 × 461 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. A built-in VESA mount version was also available.
Power supply
Power supply	143W external power adapter; power lead (2 m)	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	100% recycled aluminium in the stand; more than 15% recycled content overall	Recyclable aluminium enclosure; arsenic-free display glass; mercury-free LED backlight
Colours
Colours	Blue, Purple, Pink, Orange, Yellow, Green, Silver	–
In the box
In the box	iMac, Magic Keyboard (with Touch ID on four-port models), Magic Mouse, 143W power adapter, power lead (2 m), USB-C Charge Cable, polishing cloth (nano-texture glass only)	iMac, Magic Keyboard, Magic Mouse 2, power lead and Lightning to USB cable