A little over a year ago, many people talked about Apple's diminutive Mac mini in the past tense: As of the beginning of March 2009, it had been 19 long months since the previous update to Apple's most compact computer, and that update itself came after 11 months of waiting. Two updates in two and a half years? It was easy to believe that the Mac mini had become just as much of a "hobby" as the Apple TV.

But then we saw the March 2009 update to the mini line, the most significant update the mini had ever received. Seven months after that, the mini received another welcome, if minor, update. And here we are, just eight months later, with a new Mac mini in our hands. But whereas last March's Mac mini dramatically improved the guts of the computer and significantly enhanced its connectivity, this one, officially called the Mac mini (Mid 2010), offers more modest upgrades while revamping the mini's design for the first time since the line's debut.

In place of two non-server Mac mini models, the new Mac mini comes in a single non-server configuration that offers a 2.4GHz Core 2 Duo processor, 2GB of DDR3 SDRAM, a 320GB SATA hard drive, and nVidia GeForce 320M integrated graphics. Apart from the new graphics chip (the previous models used the nVidia GeForce 9400M), the specs of the new model fall somewhere in between those of the previous two models, which included a 2.26GHz processer, 2GB of RAM, and a 160GB hard drive, or a 2.53GHz processor, 4GB of RAM, and a 320GB hard drive, respectively. (As before, the mini ships with Snow Leopard and iLife '09.) But these minor spec changes don't tell the whole story.

Heavy metal

The most outwardly obvious change to the Mac mini is its new enclosure. While every previous mini sported a 6.5- by 6.5- by 2-inch case, the new model slims down, widens out, and gets a makeover. While still square, the mini is now 7.7 inches to a side but only 1.4 inches tall, almost the exact same size as the Apple TV, but with rounder corners. And instead of using a multi-piece body made of white plastic and aluminum, the new Mac mini adopts the all-aluminum Unibody design of Apple's current MacBook Pro line.

Mac Mini unibody

With the exception of a black-plastic panel on the back for ports and connectors, and a circular, black-plastic door on the bottom, the body of the mini is machined from a single piece of aluminum. This makes the new mini enclosure slightly heavier than that of the previous models, but the new enclosure also feels much more solid, this is the sturdiest-feeling computer I've ever used. To match the black-plastic pieces, the Apple logo on top of the Mac mini is now glossy black.

Thanks in large part to this aluminum enclosure, Apple claims the new mini is "one of the most material-efficient desktop computers available." The company also states that the new mini is the most energy-efficient desktop computer on the market, using just over 9W of power when idle but awake, and less than 1.5W when sleeping. It's also a bit quieter, and runs at least as cool, at least in my testing, than the previous model.

Notably missing from the new Mac mini's box is the bulky, heavy power brick of previous mini models. As part of the computer's redesign, and thanks to its lower power usage, Apple was able to reduce the size of the Mac mini's power supply and hide it inside the computer itself. Like the Apple TV, the Mac mini now requires only a thin power cord that plugs directly into the back of the computer. Because of this change, even though the new mini is slightly heavier, at 3 pounds, than the previous model's enclosure, once you take into account the weight of the the previous model's external power supply, the new mini is actually about a pound lighter overall.