Five millimeters thick at its edge and without an optical drive, Apple's new iMac made quite a splash today. In general, though, it's an interesting time to buy an all-in-one PC. Though Apple's been championing the idea since the very first Mac, it's about to make a lot of sense for Windows users too, as the October 26th launch of Windows 8 makes the touchscreen a priority for desktop computers. As a result, the iMac is in better company than ever before, as PC manufacturers gear up for launch. Here, we're not only going to show you how the iMac stacks up against its storied predecessors in terms of raw specs, but also vis-a-vis a host of upcoming Windows 8 competitors.

iMac vs. iMac

There's a couple of different ways to look at Apple's recent iMac progression. One is by looking at what's been taken away. Cons include no more optical drive, and no more FireWire 800 port. Pros include shedding over eight pounds of weight from each unit, and making them drastically thinner. As you can see, both the 21.5-inch and 27-inch model will still have a pretty similar footprint on your desk, but at the edges they're sexy thin like thin TVs, and the 21.5-incher is about half an inch thinner, period.

The other thing to look at is what's been added, of course. The new iMacs each cost $100 more than their predecessors did at launch, but just look at what you get: Intel's faster Ivy Bridge processors, double the memory at 8GB (and it's faster memory too), four USB 3.0 ports, an extra Thunderbolt port, and double the base storage to 1TB in the 21.5-inch model. And then there's the graphics power on tap. The 21.5-inch iMac comes with the fairly game-capable Nvidia GeForce GT 640M, with a GT 650M in the offing, and the 27-inch model comes with a GeForce GTX 660M and can house up to a GTX 680MX, a model that's likely close to parity (Nvidia won't say) with the best laptop GPU out there. Apple suggests it's got roughly 1.5 times the power of the AMD Radeon 6750M that came standard with iMacs before. Both can also be equipped with a fusion drive, an OS X-specific combination of magnetic and solid state storage.

iMac vs. the Windows 8 competition

Apple isn't the only one building loads of all-in-one computers right now, but for the first time in a while it's hard to compete with Apple on raw specs. Of the hottest new 27-inch Windows 8 all-in-one computers, only Dell's XPS One 27 manages to match the iMac's 2560 x 1440 resolution pixel for pixel, and you'll have to pay extra to get even a GeForce GT 640M, as it comes with integrated Intel graphics by default. If you're willing to drop down to 1080p resolution, Samsung's Series 7 all-in-one may be able to placate gamers with a AMD Radeon HD 7850M, though. Vizio's all-in-one manages to be a good bit lighter with its TV-like frame, but the iMac is thinner and smaller still.

Where Windows is ahead is in the ergonomics department. These Windows 8 computers all have touchscreens, and many of them have highly adjustable stands, like the Lenovo IdeaCentre A720, to angle that screen however you want. Blu-ray and DVD drives, HDMI ports, and optional TV tuners mean they can often sub in for a TV as well. Unless you watch all of your television on a computer, of course.

If you're looking for a smaller all-in-one, things are a bit more evenly matched in terms of raw specs, but Apple's 21.5-inch iMac is still ahead in the graphical department and still lacks the TV accouterments and touchscreen.

Like we said, it's an interesting time to pick an all-in-one PC.