Apple iMac 21.5in review

21 Dec 2012

An attractive new design and a host of small improvements combine to make a stunning all-in-one; it’s Apple’s best iMac so far

Price when reviewed: 
1,769(£1474 exc VAT)
Buy it now for 

A process of constant refinement has established the iMac as the best-looking desktop PC around.

Viewed head-on, you might wonder what Apple’s changed with this year’s model. Peer around the side, however, and it quickly becomes apparent: the 25mm edge of the previous-generation machine has been whittled down to an astonishing 5mm.

The iMac isn’t this thin across the whole width of the chassis. It bulges to a more accommodating 40mm in the centre where all the components are housed, but it still makes a considerable difference to the way this all-in-one looks. Approach it from an angle and it seems to float above the desk, suspended in midair.

Interestingly, Apple says this newer, sleeker iMac can’t be manufactured using the old methods, so it now uses a technique called “friction-stir welding” to join the metal section below the screen to the rear panel.

Fancy production techniques aside, though, most of the rest of the design is familiar territory. The screen is still surrounded by a glossy black border, the silver “chin” houses the familiar Apple logo and the curved stand looks as good as ever. Build quality remains sturdy, despite the trimmer profile.

All the connections are located at the back of the screen – there are four USB 3 ports, two Thunderbolt connectors, a Gigabit Ethernet socket and a headphone jack. There’s no room on the side for the SD card slot or an optical drive, however, so the former has been moved to the rear and the latter has been removed entirely.

What’s inside?

This upgrade isn’t merely superficial. Inside, Apple has made major alterations, principally to the iMac’s storage subsystem. Instead of just a hard disk or SSD, there’s the option to specify Apple’s new Fusion Drive. This combines a 128GB SSD and hard disk to provide the best of both worlds – the speed and responsiveness of an SSD and the high capacity of a hard disk.

Apple iMac 21in (2012)

The idea is to store frequently used applications and files on the SSD for improved responsiveness, while keeping less critical data on the slower, platter-based hard disk. As you might expect, the operating system resides permanently on the SSD, and a selection of key applications is placed there, too, including Safari, iMovie, iCal and iPhoto. Over time, this changes as the system learns which apps and files you use most often, moving them to the SSD, and moving those that are rarely used back to the hard disk. (Note, however, that the benefits of the Fusion Drive aren’t available to those who install Windows via Boot Camp – that’s installed on the hard disk portion of the drive.)

The effectiveness of the system will only become apparent with prolonged use, but we can say categorically that the underlying hardware is excellent.

The iMac boots quickly, taking 15 seconds to reach the desktop, and the 128GB SSD is rapid. It scored 481MB/sec and 330MB/sec in AS SSD’s sequential read and write tests – not much slower than the 497MB/sec and 340MB/sec achieved by our A-List SSD, the Samsung SSD 830.


Warranty 1 yr return to base

Basic specifications

Total hard disk capacity 1,128GB
RAM capacity 8.00GB
Screen size 21.5in


CPU family Intel Core i7
CPU nominal frequency 3.10GHz
Processor socket LGA 1155


Wired adapter speed 1,000Mbits/sec


Memory type DDR3

Graphics card

Graphics card Nvidia GeForce GT 650M
Multiple SLI/CrossFire cards? no
3D performance setting High
Graphics chipset Nvidia GeForce GT 650M
Number of graphics cards 1

Hard disk

Hard disk Apple SM128
Capacity 128GB
Hard disk usable capacity 112GB
Internal disk interface SATA
Hard disk 2 make and model Apple 1TB hard disk
Hard disk 2 nominal capacity 1,000GB
Hard disk 2 formatted capacity 931
Hard disk 2 spindle speed 5,400RPM


Resolution screen horizontal 1,920
Resolution screen vertical 1,080
Resolution 1920 x 1080


Case format All-in-one
Dimensions 528 x 175 x 450mm (WDH)

Rear ports

3.5mm audio jacks 2

Front ports

Front panel memory card reader yes

Mouse & Keyboard

Mouse and keyboard Apple wireless keyboard and mouse

Operating system and software

OS family Mac OS X
Recovery method Partition

Performance tests

3D performance (crysis) low settings 33fps
3D performance setting High
Overall Real World Benchmark score 0.96
Responsiveness score 0.83
Media score 1.05
Multitasking score 0.99

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