 This year marks the 30th anniversary of the Mac, and Apple believes its new line of personal computers are, of course, the best yet. Big new feature for the iMac is the Retina display, which has made its way to the desktop from the company's mobile devices and high-end laptops. The 27-inch display is about 5,000 by 3,000 pixels. That's 14.7 million little red-blue-green dots. Apple is calling the screen Retina 5K display, and it has seven times more pixels than an HDTV. It's also thin, really thin. The display is five millimeters at its edge. To control the display, Apple has created a new chip and is using something called Oxide TFT and a low-powered backlight. 4K video can be edited pixel for pixel with room left over for the controls and video editing software. And on top of all this, the display uses 30 percent less energy. The standard iMac comes with a 3.5 gigahertz quad-core Intel i5 processor, a Radeon R9 M290X graphic card, 8 gigabits of RAM, Thunderbolt 2, and a 1 terabyte Fusion drive, and can be upgraded to a 4 gigahertz core i7 processor, 32 gigabytes of RAM, and a 3 terabyte Fusion drive or a 1 terabyte Solid State drive. The new Retina 5K display iMac starts at $24.99. Apple will also offer a 21.5 inch iMac for $10.99 and a 27 inch iMac for $17.99, though neither of those will include the Retina 5K display.