Just as Apple‘s iPad sees a smaller profile and screen size with the new iPad Mini we previewed earlier today, the brand also takes their all-in-one computer and makes it an even more tightly-packed technical wonder. Both the 21.5 and 27-inch screen versions are 8 pounds lighter and received a new tapered design that makes them about 45 percent thinner than the previous generation. Although these are mainly aesthetic bonuses, the changes are more than skin-deep; the new iMac includes updated processing power with the addition of a new “Apple Fusion” drive, which blends a 128GB Flash memory drive with a standard hard drive that is either 1TB or 3TB in size. Both changes have ultimately allowed the machine to perform more quickly (on Mountain Lion and Aperture) while still leaving a lot of room for storage. Finally, even the screens are different, both the 21.5-inch’s 1920×1400 pixel display and the 27-inch’s 2560×1440 pixel display’s glass have been laminated to the screen just as Apple has done with the Retina Macbook and iPhone, resulting in crystal clear viewing. Bottom line: If you’re in the market for a silky-smooth and crazy fast all-in-one, now’s a good time to look at Apple’s latest iMac. The 21.5-inch model starts shipping in November for $1,200 while the 27-inch model starts at $1,799 beginning in December. View them in more detail after the jump and at the Apple iMac homepage here.