iMac (21.5-inch, 2017) vs iMac (Retina 4K, 21.5-inch, 2017)
Quick look
| Figure | iMac (21.5-inch, 2017)1 | iMac (Retina 4K, 21.5-inch, 2017)2 |
|---|---|---|
| Price | £1,0493launch price | £1,2494launch price |
| Chip | Core i52.3GHz dual-core Intel | Core i53.0GHz quad-core Intel |
| CPU | 2-coreCPU | 4-coreCPU |
| Memory | 8GBmemory, base | 8GBmemory, base |
| Storage | 1TBstorage, base | 1TBstorage, base |
| Display | 21.5-inchdisplay | 21.5-inchdisplay |
| Released | 7 June 20174ReleasedIn Apple Stores; orderable online from 5 June 2017. | 7 June 20174ReleasedIn Apple Stores; orderable online from 5 June 2017. |
| Security updates | 15 September 20255Security updates ended | 15 September 20255Security updates ended |
- Price
- The iMac (21.5-inch, 2017) is £1,049 at launch, per Apple UK Store (archived 23 June 2017); the iMac (Retina 4K, 21.5-inch, 2017) is £1,249 at launch, per Apple Newsroom (UK).
True to scale
Front faces, from Apple’s published dimensions, drawn to one scale and superposed. Corner rounding is our drawing convention, not a measurement.
Specifications
Each figure is from the source marked by its Mac’s name unless it carries its own small number, which links to where that figure was read.
Body
| Specification | iMac (21.5-inch, 2017)1 | iMac (Retina 4K, 21.5-inch, 2017)2 |
|---|---|---|
| Dimensions | 450 x 528 x 175 mm | 450 x 528 x 175 mm |
| Weight | 5.44 kg | 5.66 kg |
| Ports | Two Thunderbolt 3 (USB-C) ports, four USB-A ports, SDXC card slot, Gigabit Ethernet (RJ-45), 3.5 mm headphone jack | Two Thunderbolt 3 (USB-C) ports, four USB 3 ports, SDXC card slot, Gigabit Ethernet (RJ-45), 3.5 mm headphone jack |
| Thunderbolt ports | 2 | 2 |
| Thunderbolt version | Thunderbolt 3 | Thunderbolt 3 |
| USB-A ports | 4 | 4 |
| HDMI | No HDMI port.6 | No HDMI port.7 |
| SD card slot | Yes | Yes |
| Headphone jack | Yes | Yes |
| Keyboard | Magic Keyboard | Magic Keyboard |
| Touch ID | No Touch ID.6 | No Touch ID.7 |
Display
| Specification | iMac (21.5-inch, 2017)1 | iMac (Retina 4K, 21.5-inch, 2017)2 |
|---|---|---|
| Display size | 21.5 in | 21.5 in |
| Resolution | 1920 x 1080 | 4096 x 2304 |
| Display type | LED-backlit display | Retina 4K display |
| Brightness | Not available8 | 500 nits |
| Wide colour (P3) | Not available8 | Yes |
Chip and memory
| Specification | iMac (21.5-inch, 2017)1 | iMac (Retina 4K, 21.5-inch, 2017)2 |
|---|---|---|
| Chip | 2.3GHz dual-core Intel Core i5 | 3.0GHz quad-core Intel Core i5 |
| Apple silicon | Intel processor, not Apple silicon.9 | Intel processor, not Apple silicon.10 |
| CPU cores | 2 | 4 |
| Graphics | Intel Iris Plus Graphics 640 | Radeon Pro 555 with 2GB of VRAM |
| Chip options | 2.3GHz dual-core Intel Core i5 | 3.0GHz quad-core Intel Core i5, 3.4GHz quad-core Intel Core i5, or 3.6GHz quad-core Intel Core i7 |
| Memory (base) | 8GB | 8GB |
| Memory (maximum) | 16GB | 32GB |
| Memory options | 8GB or 16GB | 8GB, 16GB or 32GB |
| Memory upgradeable by user | No, as Apple documents11 | No, as Apple documents11 |
| Storage (base) | 1TB | 1TB |
| Storage (maximum) | 1TB | 1TB |
| Storage options | 1TB hard drive, 1TB Fusion Drive or 256GB SSD | 1TB hard drive, 1TB Fusion Drive, or 256GB, 512GB or 1TB SSD |
Connectivity
| Specification | iMac (21.5-inch, 2017)1 | iMac (Retina 4K, 21.5-inch, 2017)2 |
|---|---|---|
| Wi-Fi | 802.11ac Wi-Fi | 802.11ac Wi-Fi |
| Bluetooth | 4.2 | 4.2 |
| Ethernet | 10/100/1000BASE-T Gigabit Ethernet (RJ-45) | 10/100/1000BASE-T Gigabit Ethernet (RJ-45) |
| External displays (base) | 2 | 2 |
Sources
Apple Support (UK) — iMac (21.5-inch, 2017) - Technical Specifications ·
↩Apple Support (UK) — iMac (Retina 4K, 21.5-inch, 2017) - Technical Specifications ·
↩- ↩
- ↩
endoflife.date — Apple macOS ·
↩iMac (21.5-inch, 2017): No HDMI port. No Touch ID.
↩iMac (Retina 4K, 21.5-inch, 2017): No HDMI port. No Touch ID.
↩Not published by Apple.
↩iMac (21.5-inch, 2017): Intel processor, not Apple silicon.
↩iMac (Retina 4K, 21.5-inch, 2017): Intel processor, not Apple silicon.
↩Apple Support (UK) — Install memory in an iMac ·
↩Apple Support (UK) — Identify your iMac model ·
↩
Not published by Apple
iMac (21.5-inch, 2017). Apple doesn’t publish for this Mac: colours, pixel density, refresh rate, nano-texture option, GPU cores, storage upgradeable by user, maximum continuous power, the macOS it shipped with. Geekbench 7: the Mac chart has no entry for this Mac, so no figures are shown (chart read 10 Oct 2026). Pages checked: Apple Support (UK) — iMac (21.5-inch, 2017) - Technical Specifications; Apple Support (UK) — Identify your iMac model; Apple Newsroom (UK) — iMac receives major update featuring more powerful graphics, faster processors, Thunderbolt 3 and brighter displays, read 9 Oct 2026.
iMac (Retina 4K, 21.5-inch, 2017). Apple doesn’t publish for this Mac: colours, pixel density, refresh rate, nano-texture option, GPU cores, storage upgradeable by user, maximum continuous power, the macOS it shipped with. Geekbench 7 Metal: the Mac chart has no Metal score for this Mac (chart read 10 Oct 2026). Pages checked: Apple Support (UK) — iMac (Retina 4K, 21.5-inch, 2017) - Technical Specifications; Apple Support (UK) — Identify your iMac model; Apple Newsroom (UK) — iMac receives major update featuring more powerful graphics, faster processors, Thunderbolt 3 and brighter displays, read 9 Oct 2026.
If you own one of them
Whether to move is a different question from which is better. Each Mac has a page on it: what its successor changes (the newest Mac in its line where Apple sells one, otherwise the Mac this site treats as its replacement, which can be in another line), what it fetches and whether it still gets updates. Should I upgrade my iMac (21.5-inch, 2017)? · Should I upgrade my iMac (Retina 4K, 21.5-inch, 2017)?
Other comparisons
The pairs a buyer of either Mac would also weigh. Any two Macs in the catalogue can be compared from the chooser.