Review: Apple's new 21.5-in. iMac

Review: Apple's new 21.5-in. iMac

There's something different about Apple's latest iMac, and it's obvious even before you see it. The peculiarly shaped box it ships in hints at the design changes made to this model, which was unveiled by Apple in October and is only now shipping in significant numbers.

The big difference is the thinner aluminum housing around the screen, which now tapers to just 5mm at the edge -- an amazing 80% reduction in thickness compared to its predecessor. It's immediately noticeable and it looks impressive, especially from any angle in which the side, top, or bottom of the iMac is displayed.

But the changes are more than external. The new iMac -- still available in 21.5-in. and 27-in. screen sizes -- features an Ivy Bridge architecture powered by either an Intel Core i5 or i7 processor, faster graphics chipsets from NVIDIA and an optional solid-state drive/hard disk drive combo that Apple calls a Fusion Drive. This last change stands out as closest to the cutting edge of technology you'll find in the iMac -- but with a big caveat. More about that below.

The new iMac line was unveiled in late October after going almost a year and a half without an update. (The last version arrived in May 2011). Shipments of the smaller model, which starts at $1,299, began shortly after Thanksgiving -- barely in time for the holiday shopping season. The larger, 27-in. iMac starts at $1,799 and is only now beginning to trickle out.

The sluggish rollout is unusual for Apple, which stopped selling the previous iMacs before the new ones actually arrived.

Specs and details

The 21.5-in. version comes in two basic models, both of which feature a 1920-x-1080-resolution display. The $1,299 iMac uses a 2.7GHz quad-core Core i5 processor with 6MB of L3 cache and the ability to use Turbo Boost to push the processor to 3.2GHz when needed. The $1,499 iMac has a faster 2.9GHz quad-core Core i5 (also with 6MB of L3 cache) and can top out at 3.6GHz with Turbo Boost. The latter iMac can also be ordered with a Core i7 quad-core chip running at 3.1GHz (with a Turbo Boost speed up to 3.9GHz) for an additional $200.

Both of the smaller iMacs come with 8GB of 1600MHz DDR3 RAM, though you can double the memory to 16GB for $200. But here's the kicker: You can't upgrade the memory after you buy. So if you think you'll want 16GB of RAM down the road, order it that way now. (In contrast, the 27-in. iMac has four user-replaceable memory slots, so you're not locked into 8GB of RAM.) For comparison purposes, the larger iMacs offer more than bigger screens: they cost more, too. The basic 27-in. model starts at $1,799 and comes with the same i5 chip as the $1,499, 21.5-in. iMac. The $1,999 model gets you a Core i5 processor running at 3.2GHz, though you can move up to a Core i7 running at 3.4GHz for $200 more if you need more processing power. You also have more storage options on these models, including a 768GB SSD drive that will set you back $1,300.

All of new iMacs come with a 1TB hard drive and a NVIDIA graphics cards, starting from a GeForce GT 640M in the entry-level model to a GeForce GT 650M in the $1,499 version. The larger iMacs get either a GeForce GTX 660M or a GeForce GTX 675MX to drive the 2560-x-1440-resolution screen. Any of the NVIDIA cards should be enough to power most games and graphics-heavy apps for the life of the iMac.

Rounding out the standard iMac feature list are stereo speakers (which sound pretty good, but won't satisfy hard-core audiophiles), dual microphones (used for noise-canceling when conducting FaceTime video chats or using the built-in dictation), a headphone port (which supports headphone/optical audio output), four USB 3.0 ports, two Thunderbolt ports for peripherals, an SDXC slot and Gigabit Ethernet. There's also a 720p FaceTime video camera, 802.11a/b/g/n Wi-Fi and low-power Bluetooth 4.0.

Design pluses and compromises

The iMac Apple provided for this review is 17.7-in. high and 20.8-in. wide, and weighs a svelte 12.5 lb. As with previous models, the overall look is minimal and clean, with an inch-thick black border framing the screen. Viewed strictly head-on, the new iMac looks pretty much like the last model. But looking at the new aluminum chassis from any other angle showcases how thin the housing is. It's a seriously elegant design ... and clearly a show-off move, done more for ooohs and ahhhs. Credit (or blame) Apple's design guru Jonny Ive.

I say that because the machine's footprint is the same; this iMac won't take up any less desk space than the last model, so the decrease in size and volume is more about form than function.

Even so, the fact that Apple's engineering team went out of its way to tweak the exterior case shows how much Apple values design. Superficial move or not, this iMac is a stunner.

The thin enclosure is possible because Apple engineers used a process called friction-stir welding to combine the front chin of the iMac with the rear piece, while maintaining the 5mm-thin edge wall. The technique is more commonly used in the construction of airplane wings, rocket booster tanks and high-speed trains.

As thin as the sides are, the iMac isn't really that thin around back. There's a gentle bulge on the iMac's rear that provides room for the internal circuitry.

While the iMac's design is impressive, the thinness comes at the expense of the now-missing Super Drive, Apple's CD/DVD writer/reader. You can purchase an external drive that connects via USB for an additional $79, but Apple is clearly shifting its ecosystem away from discs to an in-the-cloud future.

Bright screen, vivid colours

Like other iMacs, the display is clearly the focus, and it doesn't disappoint, even though it's not as sharp as the Retina displays on the latest MacBook Pros, the iPad and the iPhone. LED backlighting means there are no bright splotches to disrupt color uniformity; IPS technology delivers a consistent and vibrant picture from even extreme angles with surprisingly little color shift. And because each display goes through a color-calibration process using three separate spectroradiometers, it looks incredible out of the box without tedious calibration.

The screen is still glossy, but reflections are less noticeable now; Apple touts a 75% reduction in glare. Apple managed to accomplish this by using a couple of techniques. First, it eliminated the old 2mm gap between the display and the glass; the two are now bonded together using a process called full lamination.

Second, atom-wide layers of silicon dioxide and niobium pentoxide are coated against the front glass in a process called plasma deposition. Those technical details aside, I can confirm the screen is not as glossy as it used to be.

The pixel density is certainly fine for a screen this size. But I've been spoiled by Apple's Retina displays, which feature pixels so densely packed that they're not really discernible to the naked eye. The result is crystal-clear text, ultra-sharp graphics, and -- with high-resolution media -- demo-worthy show pieces. That's not to diminish how good the monitor is, just to note that if you're used to staring at a Retina screen, you may notice the pixels here.

As before, the screen can only swivel up and down. If you need to move it side-to-side, you're going to have to shift the entire unit. Despite its size, the screen is easy to adjust with one finger and stays exactly in place once positioned.

Note also, that the iMac can be used as an external monitor for any Thunderbolt-equipped computer connected via Thunderbolt cable. Just press Command-F2 on the keyboard, and you can instantly mirror or extend your desktop onto the iMac's screen. It works great with the 15-in. MacBook Pro I tested it with.

Even better? While performing my typical benchmarks (some of which take a lot of time), I was able to switch the iMac to Target Display Mode so I could use it as an external monitor for my notebook while the iMac continued to process its jobs uninterrupted in the background.

The colors shown on the MacBook Pro's Retina display were consistent with those on the iMac. I use multiple monitors each day, so I immediately noted the color consistency and uniformity across screens. Apple's monitor calibration at the factory does indeed has real-world benefits; I was impressed.

Storage and the Fusion Drive

I mentioned earlier that the low-end iMac ships with a standard 1TB drive; that's plenty of space for most users, but there's a wrinkle: It's a 2.5-in. laptop drive that spins at just 5,400rpm. In other words, Apple opted for capacity over hard drive speed, even though a 7,200rpm drive would deliver better performance. (The larger 27-in. iMac uses a 3.5-in., 7,200rpm drive.)

For an additional $250, Apple offers a 1TB Fusion Drive like the one that came in the review iMac, which helps speed things up considerably. The Fusion Drive is, literally, two drives acting as one -- an SSD for fast data access and a traditional rotating drive for more storage.

What you see is one hard drive, but the operating system automatically figures out which data or apps you access most, and puts that on the much faster SSD; everything else is relegated to the slower, but higher capacity, hard drive. This is the technological equivalent of having your cake and eating it, too; by utilizing the strengths of each drive, the iMac can have the speediness of SSD without sacrificing storage capacity.

If you want SSD speed, you'll have to get the Fusion drive, since Apple doesn't offer a standalone SSD upgrade. There's always the option of booting from an external SSD using the Thunderbolt connection (something that's actually really effective, as long as no one ever unplugs that drive). But that does little to avoid the frustration of a limited set of options, both of which utilize the slower 5,400rpm drives.

The review unit shipped with a Fusion Drive, and using the Blackmagic Disk Speed Test, I got test results showing write speeds averaging between 295MBit/sec. and 320MBit/sec., and read speeds between 390MBit/sec and 445MBit/sec. So I expected this iMac to perform well in my own custom benchmark.

Whenever I review a Mac, for consistency's sake I have a complex, 50-minute iMovie project that I like to render. (The iMovie file was exported using Apple's "Large" settings, resulting in an h.264 m4v file with a 960-by-540-pixel resolution.) A 2.8GHz quad-core i5 iMac from 2010 rendered the movie project in an hour and eight minutes; the iMac I tested last year did it in just 48 minutes.

How did this one do? It rendered the movie in a disappointing 51 minutes, three minutes slower than last year's iMac. Blame the 5,400rpm drive. Everything runs snappily when the data is coming from the fast SSD, but when you have large files (such as movies used in iMovie projects like my test file) stored on the hard drive part of the Fusion Drive, it really slows things down -- even though the iMac has a better processor and system architecture. This brings us back to the lack of hard drive options earlier; a 7,200rpm drive, or a larger SSD, would have been a nice option on the smaller iMac to help alleviate this kind of bottleneck.

Although the Fusion Drive generally delivers on the promise of more speed and higher storage, let's be realistic. It's two hard drives acting as one. So be sure to purchase an external drive and use Time Machine (or any number of free backup utilities) to regularly back up your system. That's standard advice these days, but even more important when you're on the cutting edge of tech. Do your backups.

Real world use

After pulling the iMac out of the box, I used the Migration Assistant's "import from hard drive" option and put my Retina display Mac Book Pro into Target Disk Mode. (Hold down the T key at startup.) Using a Thunderbolt cable, Migration Assistant was able to transfer 151GB of Applications, settings, and data from one machine to the other with ease. Here's where I geeked out a bit: We all know SSD drives are fast, and Thunderbolt is supposed to be a fast connection. But the real-world results were stunning. All 151GB of data was transferred in less than 10 minutes.

I was up and running on the iMac using an exact clone of my laptop files less than 20 minutes after taking the iMac out of the box.

During use, when the house became really quiet, I could hear the slight whir of the iMac's fan, but I really had to listen for it. The machine itself never ran hot, although the rear casing became slightly warm during heavy processing in certain areas.

OS X Mountain Lion was as stable as always in daily use, although I did have issues exporting projects from iMovie '11, which often halted the rendering process to display some random error. This issue -- a common complaint regarding iMovie -- was the only problem I ran into.

Since you're using OS X, it makes sense to get the most out of its capabilities. To that end, I recommend buying the Magic Trackpad instead of relying on Apple's Magic Mouse. Apple's trackpads are really precise and will feel natural if you are already using the iPad and are accustomed to gestures. As iOS is on the iPad and iPhone, Mountain Lion on a desktop machine takes advantage of multitouch technology and offers swiping, pinching and other gestures that really make your workflow easier.

Although Apple may have cut some corners by using a 5400 rpm drive in the 21.5-in. iMac, it certainly didn't skimp elsewhere. For most day-to-day tasks, the iMac performs well, if not spectacularly. If you want this iMac to perform at the top of its game, opt for the Fusion Drive and the 16GB of memory.

As was the case with the previous generation of iMacs, this isn't a machine for tinkerers, so max out the memory when you buy; this will extend the useful life of the iMac. And there's no access to any other parts, so any future upgrades like extra storage will have to be external, which is why the inclusion of the Thunderbolt connections are so important.

That said, if you're looking for a solid all-in-one desktop that looks stunning, performs well, and features a gorgeous display (which can be used as an external monitor by another Mac), this iMac should fit the bill. Just be aware of the aforementioned tradeoffs when buying.

Michael deAgonia, a frequent contributor to Computerworld, is a writer, computer consultant and technology geek who has been working on computers since 1993. You can find him on Twitter (@mdeagonia).

Follow Us

Join the newsletter!


Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags Applehardware systemsdesktop pcsMac desktops


Show Comments