The iMac "Core i5" 3.2 27-Inch Aluminum (Late 2013/Haswell) features
a 22 nm "Haswell" Quad Core 3.2 GHz Intel "Core i5" (4570) processor with
four independent processor cores on a single chip,
a 6 MB shared level 3 cache,
16 GB of 1600 MHz DDR3 SDRAM (PC3-12800) installed in pairs (two 4 GB modules),
a 256 GB solid state drive, and
a NVIDIA GeForce GT 755M graphics processor with
1 GB of dedicated GDDR5 memory.
It also has a built-in "FaceTime HD" webcam and stereo speakers, but lacks an optical drive.
This model has
a 27" 2560x1440 LED-backlit
16:9 widescreen IPS display
with the "cover glass fully laminated to the LCD and anti-reflective coating."
The rear of the case is aluminum and is thicker in the middle and tapers to a razor thin 5 mm at the edges.
four USB 3.0 ports,
dual Thunderbolt ports,
802.11ac Wi-Fi (802.11a/b/g/n compatible), and
Compared to its predecessor, this model essentially has the same external enclosure, but it has a much more efficient "Fourth Generation" processor and architecture, as well as faster graphics, faster Wi-Fi, and the option of faster storage.
Please note that stock images are used