With 21.5” Display (diagonal) LED-backlit, a resolution of 1920 x 1080 that supports for millions of colors and a 16:9 aspect ratio. IPS Display. This iMac simultaneously supports full native resolution on the built-in display at millions of colors (21.5-inch) or 1 billion colors (21.5-inch 4K) with following; one 5120 x 2880 (5K) external display at 60 Hz with support for 1 billion colors, or two 3840 x 2160 (4K UHD) external displays at 60 Hz with support for 1 billion colors, or two 4096 x 2304 (4K) external displays at 60 Hz with support for millions of colors.
The Processor on the iMac 21.5″ Mid 2017 come’s with 7th Generation Kaby Lake processor “Dual Core” Performance with a 2.3 GHz and can be “overclocked” Turbo Boost up to 3.6 GHz. The Kaby Lake 7th Gen. Processor is low on voltage and still provides a better and a fast performance that’s need to run the processor for multi-tasking jobs.
The Ports on this iMac are; (Four) USB 3 ports (compatible with USB 2), SDXC card slot, 3.5 mm headphone jack, 10/100/1000BASE-T Gigabit Ethernet (RJ-45 connector), (Two) Thunderbolt 3 (USB-C) ports with support for: ( Display port; Thunderbolt (up to 40Gb/s); USB 3.1 Gen 2 (up to 10gb/s); Thunderbolt 2, HDMI, DVI and VGA supported using adapters (Sold Separately).