iMac Ci5 2.5GHz 4GB 500GB DVD-RW 21.5"

Today's iMac has come a long way from the first 15-inch iMac. Take one look and you'll see just how far. A display with edge-to-edge glass covers nearly the entire front of the enclosure. When all you see is the display, nothing gets between you and what's onscreen. Movies, TV shows, FaceTime HD video calls, websites, photos - everything looks stunning on the widescreen 16:9 iMac display.The more pixels a display has, the more light those pixels need to achieve the best picture possible. And that's exactly what the LED backlighting in iMac does: it pushes light through each pixel with remarkable brightness and efficiency. Because the LED backlight doesn't take up much space, the iMac enclosure stays thin - even with all the high-performance components inside.The widescreen iMac display allows more room to separate the two hottest components, the CPU and the GPU. This keeps things cool inside the iMac enclosure. Apple engineers also implemented an intelligent control system that monitors temperatures and delivers just the right amount of airflow to critical components. And the three fans inside iMac have been tuned to be ultra quiet, so you hardly know it's on.Watching a movie, updating your blog, editing photos. Tasks like these require data to travel from place to place. The Intel Core architecture puts the processor, cache, memory controller, and graphics engine on a single chip. Since data doesn't have as far to travel, you get faster performance and greater efficiency.Thunderbolt technology has arrived - and Apple computers are the first to have it. With one tiny port, you get lightning-fast transfer speeds and huge expansion capabilities. Two 10-Gbps data channels per port mean you can transfer data up to 12 times faster than with FireWire 800. And don't worry about a single drive or peripheral tying up the Thunderbolt port: you can daisy-chain as many as six devices plus a display.