Here's iMac's 21.5-inch Lineup

First Look at 21.5-inch iMac Retina 4K Display

2015 Retina iMac 21.5 and 27 inch models
Courtesy of Apple

Apple took the wraps off a new 2015 21.5-inch iMac lineup that uses new Broadwell-based processors, faster Intel integrated graphics, and, as expected, a new Retina 4K Display model, finally bringing Retina image quality to the smaller of the iMacs.

The new 21.5 iMac lineup is divided into three basic configurations: a baseline and a mid-level model, both with the standard 1920 x 1080 display used in previous generations, and a high-end configuration that includes the Retina 4K display, with 4096 x 2304 pixels.


It’s been a long wait, but the 21-5-inch iMacs will be configured with Broadwell-based processors from Intel. On the bright side, the Broadwell chips will provide a nice boost in overall performance, when compared to the older Haswell-based iMacs. But I’m a bit surprised that the newest Skylake processors, which Apple incorporated into the 2015 27-inch iMac, weren't included; this would have allowed Apple to just skip over the Broadwell family.

I imagine the issue was cost, as the Skylake processors are still very new, and continue to command a bit of a premium in price. However, let’s not get too wrapped up in the processor’s name, when what's really important is how well the new iMacs will perform.

The base model makes use of a 1.6 GHz Dual-Core i5, while the mid-level iMac jumps up to a 2.8 GHz Quad-Core i5. The Retina version of the 21.5-inch iMac comes with a 3.1 GHz Quad-Core i5. The Retina iMac offers processor upgrades, letting you bump the processor to a 3.3 GHz Quad-Core i7, which should provide quite a punch in CPU performance.


All of the 2015 21.5-inch iMacs make use of integrated graphics from Intel. The baseline model comes with the Intel HD Graphics 6000, the same GPU used in the MacBook Air.

The Retina version of the 21.5-inch iMac uses the more powerful Intel Iris Pro Graphics 6200. Unlike the 27-inch Retina iMac, there are no graphics upgrades available. However, since the 21.5-inch iMac uses a smaller 4K display, versus the 5K display in its big brother, the 6200 integrated graphics should provide very good graphics performance, including the ability to drive both the iMac’s native Retina display and an external 4K display connected via the Thunderbolt 2 port.


Built-in storage on the 2015 21.5-inch iMacs is a bit of a mixed bag. The standard configuration on all of the iMacs is a 1 TB hard drive that spins at 5,400 RPM. That’s a pretty good choice for a Time Machine backup drive, but as a daily startup drive, it's less than ideal. The slow rotation rate guarantees a bottleneck in performance, and will likely cause you to gnash your teeth every time you boot your iMac or launch an application, as you either wait for your desktop to appear or your Dock icons to stop bouncing.

Luckily, you can upgrade to a new version of the 1 TB Fusion Drive or a very fast SSD as your primary storage. The 1 TB Fusion drive has undergone a slight tweak. Originally, the Fusion drive was made up of a 128 GB SSD and a 1 TB hard drive. But Apple changed the 1 TB Fusion Drive to make use of a much smaller 24 GB SSD. This should still provide enough storage to ensure that OS X and quite a few of the apps you use most often are stored on the high performance SSD, but it won’t leave as much additional room as the original version of the Fusion Drive. On the bright side, the cost of the 1 TB Fusion option is now much lower, and the 2 TB Fusion option still uses the larger 128 GB SSD.


There doesn't appear to be any change in the port configurations; a headphone jack, SDXC card slot, four USB 3 ports, two Thunderbolt 2 ports, and a Gigabit Ethernet jack round out the connections on the back of the iMac.

Wireless connectivity includes 802.11ac Wi-Fi and Bluetooth 4.0.

iMac Base iMac Medium iMac Retina 4K
Processor 1.6 GHz Dual-Core i5 2.8 GHz Quad-Core i5 3.1 GHz Quad-Core i5
RAM 8 GB 8 GB 8 GB
Storage 1 TB hard drive 1 TB hard drive 1 TB hard drive
Graphics Intel HD Graphics 6000 Intel Iris Pro Graphics 6200 Intel Iris Pro Graphics 6200
Display 1920 x 1080 sRGB 1920 x 1080 sRGB Retina 4K 4096 x 2304
Price $1,099.00 $1,299.00 $1,499.00
3.3 GHz Quad-Core I7 +$200
16 GB RAM +$200 16 GB RAM +$200 16 GB RAM +$200
1 TB Fusion Drive +$100 1 TB Fusion Drive +$100 1 TB Fusion Drive +$100
256 GB SSD +$200 2 TB Fusion Drive +$300 2 TB Fusion Drive +$300
256 GB SSD +$200 256 GB SSD +$200
512 GB SSD +$500
2015 21.5-inch iMac Configuration Chart


The base model of the 2015-21.5 iMac has an attractive price, but really, that's about all you can say about it. It's saddled with a slow hard drive and mediocre graphics. Its place in the lineup is to allow Apple to advertise a low price that will appeal to corporate and educational buyers.

For general use, I recommend the middle price point non-Retina model that starts at $1,299. To this I would add the 1 TB Fusion Drive upgrade (+ $100), to give the iMac a bit of pep and to get around the slow performance of the 5400 RPM drive used in the basic configuration.

You may also want to consider upgrading the RAM, which, like the storage, can only be upgraded at the time of purchase; there are no user-upgradeable parts within the 21.5-inch iMac.

If you fancy the Retina display, and really who doesn’t, the same recommendations apply; an upgrade to the basic storage configuration, either a Fusion Drive or the SSD, and an upgrade of RAM to 16 GB.

In the end, a 2015 21.5-inch Retina iMac with upgraded storage and RAM can put you at the same price point as the entry-level 27-inch iMac with Retina 5K Display, which uses the newer Skylake processors, a faster hard drive, dedicated graphics, and a larger 5K display. If physical size isn't a limiting factor, I'd jump to the 27-inch Retina iMacs.

Find out more about the 2015 21.5-inch iMac lineup.