The iMac "Core i5" 2.7 21.5-Inch Aluminum (Late-2013) features a Quad Core 2.7 GHz Intel "Core i5" (4570R) processor with four independent processor cores on a single chip, a 4 MB shared level 3 cache, 8 GB of 1600 MHz DDR3 SDRAM.
Although the iMac Intel Aluminum came with 8 GB of RAM it could be upgraded up to 16 GB of RAM.