Apple 27" iMac with Retina 5K Display (Late 2015)

Apple weds high-res 5K visuals into its sleek 5mm thin 27" iMac with Retina 5K Display. With a 5120 x 2880 native resolution, this iMac provides 14.7 million pixels, which is 7 times more than the standard HD display. The Retina 5K display also features a wider color gamut. Using a P3-based color gamut, the Retina 5K display provides a 25% larger color space than standard sRGB displays. And with more available colors, the images will appear more vivid and reveal greater detail.
The iMac houses a quad-core 6th-gen Skylake 3.2 GHz Intel Core i5 processor with 8GB of 1867 MHz DDR3 RAM. The iMac also has an AMD Radeon R9 M380 graphics card with 2GB of GDDR5 vRAM. For storage, the iMac has a 1TB 7200 rpm HDD.
Outfitted with 802.11ac Wi-Fi (backwards compatible with 802.11a/b/g/n) for the speediest hook-ups to your home network, this iMac is also configured with Bluetooth 4.0, as well as an SDXC card slot for extra storage, four USB 3.0 ports, two Thunderbolt 2 ports, and a Gigabit Ethernet (RJ-45) jack. It also has a Kensington lock slot for added security.
The iMac runs the Mac OS X El Capitan operating system. Built on a solid UNIX foundation, El Capitan is engineered to take full advantage of the iMac's hardware. It features performance improvements and updates to built-in apps. El Capitan was specifically designed for the Retina display and features a system font called San Francisco that has been fine-tuned for optimal readability on a Retina display.
For ports, the iMac has dual Thunderbolt 2 ports (which also double as Mini DisplayPorts) and four USB 3.0 ports. You'll be able to connect with various compatible components. If you would rather go wireless with your peripherals, you can use Bluetooth 4.0 technology where compatible.

27" Retina 5K IPS Display

Whether your iMac is in your studio, living room, or kitchen, the display is the focal point. With a 5120 x 2880 resolution, the iMac with Retina 5K display features 14.7 million pixels, which allows for crisp, clear text and support for 4K photos and videos. The IPS panel allows for wider viewing angles so more people can enjoy the Retina 5K display without having to crowd around it.

6th-Gen Skylake Quad-Core Intel Core Performance

The iMac houses a quad-core 6th-gen Skylake Intel Core i5 processor. Its quad cores can reach a stock speed of 3.2 GHz. It can also be overclocked up to 3.6 GHz, thanks to Intel Turbo Boost 2.0 technology. The 6th-gen Skylake Intel processor uses low voltage for better energy efficiency while still providing fast performance. Combined with 8GB of 1867 MHz DDR3 RAM, the iMac allows you to multitask quickly and efficiently.

Impossibly Thin

The iMac with Retina 5K display maintains its 5mm profile, which is up to 40 percent less volume than the 2011 iMac. Using an advanced welding method called friction-stir welding, Apple was able to join the front and the back of the iMac together directly.

802.11ac Wi-Fi & Bluetooth 4.0

With three-stream 802.11ac technology, the iMac takes desktop Wi-Fi speeds over the top. When it's connected to an 802.11ac base station - including AirPort Extreme and AirPort Time Capsule (both sold separately) - you can reach data rates of up to 1.3 Gbps. That's triple the previous 802.11n standard, which means you'll get up to three times faster Wi‑Fi. You also get double the channel bandwidth, with 80MHz-wide channels providing more room for more data to flow faster than ever. Bluetooth 4.0 wireless technology is also built in, so you can connect accessories such as a wireless keyboard and mouse.

Thunderbolt 2

Expand the capabilities of your Mac. Connect high-performance peripherals. Transfer data at high speed. Even daisy-chain multiple devices. And the iMac with Retina 5K display has Thunderbolt 2, delivering twice the bandwidth - up to 20 Gbps - for fast data transfers. While the Thunderbolt 2 ports double as mini DisplayPorts, the iMac with Retina 5K display cannot be used as a standalone monitor like its predecessor. It can, however, be used simultaneously with an external display and can output up to a 5120 x 2880 resolution.

USB 3.0

With USB 3.0, you can transfer large files in seconds instead of minutes. Every iMac comes with four USB 3.0 ports - with speeds up to 10 times faster than USB 2.0 - and you can connect all your USB-compatible devices, including your iPhone, iPad, iPod or digital camera.

Mac OS X El Capitan

The iMac comes with OS X El Capitan, which refines the Mac experience and improves system performance. El Capitan builds on the features and design of OS X Yosemite, with updates to window management, built-in apps and Spotlight search, and performance improvements to make everyday activities - like launching and switching apps, opening PDFs and accessing email - faster and more responsive. El Capitan was specifically designed for the Retina display and features a system font called San Francisco that has been fine-tuned for optimal readability on a Retina display.