Apple iMac 21.5-inch (December 2012) review: The smaller iMac Windows PCs can pick on

Yes, for better or for worse, those other PCs have Windows 8. They also have touch screens and optical drives, features that Apple has deemed inessential for a desktop. You might agree with Apple. You might also accept Apple's hallmark design excellence and display quality as worthy substitutions. You might even need or want a particular function of OS X that you can't get in a Windows PC.

Judged purely by its hardware, however, the 21.5-inch iMac is an expensive all-in-one with less functionality than its competition. I would not recommend it to someone looking for the most computer for his or her dollar.

I don't have much to add about the design of the 21.5-inch iMac that I didn't already mention in the review of the more expensive 27-inch model.

As evidenced by the iMac's thin-seeming profile and clean appearance overall, Apple's design lead over the rest of the PC industry remains healthy. You can count me among those who felt disappointed that the new, bulge-backed iMacs were not as thin as Apple originally presented them as being. I quickly got over that disappointment after spending a few minutes with the new design.

Like the 27-inch iMac, the 21.5-inch model has a rounded protrusion on the back of the screen that houses the computing components. You will only notice the bulge when you look at the screen from the most oblique angles. You don't notice its thinness either when you're sitting directly in front of the iMac, but from most other vantage points, the screen appears as thin as its 5-millimeter edge.

That new chassis has only a cosmetic impact on the user. More functionally meaningful in theory is a new glare-resistant screen coating intended to address complaints about too much environmental reflectivity on the previous-generation iMacs.

Our lab -- all long, bright, overhead fluorescents -- is a challenging environment for glare testing. I no longer have the 27-inch iMac on hand to compare, but I know I noticed the reduced glare on the big-screen model when I reviewed it. My impression is that the 21.5-inch iMac is more reflective than the 27-inch version.

I don't have the means to objectively measure reflectivity. My impression could be due to variability in the coating between applications. It could also be a function of the absolute size of the reflected light source hitting the 21.5-inch iMac's comparably smaller viewing area. In any event, while the apparent difference is not enough to ruin the iMac's usability, if you're undecided on screen size and glare is a concern, you might head down to your local Apple Store and compare the screens yourself.

I include the Vizio CA24T-A4 in the above comparison to highlight multiple Windows PCs that have larger screens than this iMac, but the Asus ET2300INTI is the more challenging comparison for Apple. The Asus system also has a larger screen, as well as a faster CPU than the iMac.

Like many Windows all-in-ones, the Asus ET2300INTI has an HDMI input, as well as an HDMI output. Before you call out the iMac's Thunderbolt ports, know that the Asus has two of them. On the iMac, you'll need to use one of the Thunderbolt ports and connect an adapter in order to use it with an HDMI-based device, adding expense and complication.

The combination of HDMI and Thunderbolt gives the Asus a significant edge over the iMac in terms of its out-of-the-box connectivity options. Yes, the Asus also has built-in WiDi capability, an eSATA port, and the aforementioned touch screen and DVD burner, but it's the combination of ports that really extends its usability. With HDMI alongside Thunderbolt, you can connect a cable box, a game console, an HD camcorder, or some other assortment of video source devices to the Asus system, adapter-free, and still have room to add a fast Thunderbolt data array. With the iMac you'll need a bird's nest of expensive adapters or Thunderbolt cables or both for the same functionality.

How many people will actually use those inputs on either system, much less in combination? Great question, and I don't know the answer. But I do know that, all else equal, I'd rather my $1,299 afforded me the most convenient option.

Cinebench 11.5
(Longer bars indicate better performance)

Rendering multiple CPUs

Rendering single CPU

Asus ET2300INTI (3GHz Core i5, November 2012)

4.98 

1.35 

Apple iMac 21.5-inch (2.7GHz Core i5, November 2012)

4.44 

1.28 

Vizio CA24T-A4 (2.5GHz Core i5, November 2012)

2.87 

1.28 

Don't make too much of the performance difference in our charts. Between the iMac and the Asus system, the only statistically significant variability shows up on our iTunes MP3 conversion test, and the Asus system can certainly be forgiven for trailing the iMac on Apple-made software. Our test with HandBrake and iTunes converting files simultaneously is a much more challenging benchmark, and in that case the two systems have basically identical performance.

Gaming on either system is not an impossible prospect, although the 1,920x1,080-pixel-resolution displays will challenge their lower-end Nvidia graphics chips if you play demanding games at high image quality. The Witcher 2 on the iMac, for example, was not the most playable experience, but at lower image quality settings it's at least possible. The same goes for the Asus.

Along with the iMac's Thunderbolt ports, you also get four USB 3.0 ports, an Ethernet jack, an SDXC card slot, and a headphone output that doubles as a digital audio jack. Like the 27-inch model, the 21.5-inch version has a pair of microphones that work in concert to minimize background noise during video chats. You do not, however, get user-accessible system memory in the 21.5-inch iMac, adding expense and hassle for those who might want to expand the default 8GB of memory. These new iMacs are also not wall-mountable.

Conclusion
Apple's 27-inch iMac is an Editors' Choice award winner for its large, high-resolution display and its high performance system components. The 21.5-inch version is also a fine computer, but its comparatively lower price puts it in more competitive waters. You can get more performance, including Apple's hybrid solid-state Fusion hard-drive option, by paying more, but at that point you enter even more challenging Windows PC territory with the non-touch version of Dell XPS One 27 looming for a mere $1,399.

Some need or some emotion-driven want may compel you to buy the 21.5-inch iMac, and if that happens you will own one of the best-designed computers available. If instead you're looking for the most functional capability hardware for the dollar, I would encourage you to comparison-shop, and weigh the Asus ET2300INTI in particular as an alternative.

All performance testing conducted by Joseph Kaminski. Find out more about how we test desktop systems.

System configurations

Apple iMac 21.5-inch (November 2012)
Apple OS X Mountain Lion 10.8; 2.7GHz Intel Core i5-3330S; 8GB 1,600MHz DDR3 SDRAM; 512MB Nvidia GeForce GT 640M graphics card; 1TB 5,400rpm hard drive

Asus ET2300INTI
Microsoft Windows 8 (64-bit); 3GHz Intel Core i5-3330; 8GB 1,333MHz DDR3 SDRAM; 1GB Nvidia GeForce GT 630M graphics card; 1TB 7,200rpm hard drive

Vizio CA24T-A4
Microsoft Windows 8 (64-bit); 2.5GHz Intel Core i5-3210M; 6GB 1,600MHz DDR3 SDRAM; 32MB Intel HD Graphics 4000 (embedded); 1TB 5,400rpm hard drive