Question: where is the processor located in an imac

title: iMac (Intel-based)
text: A Retina Display `` 5K '' model with a resolution of 5120 × 2880 was introduced alongside the previous year 's models during a keynote on October 16 , 2014 . This 27 - inch model was given faster Haswell processors and its two Thunderbolt ports were updated to Thunderbolt 2 . Secondary storage was also upgraded to a 1 TB Fusion drive as standard and video options changed over to AMD Radeon R9 M290X and M295X . A 21.5 - inch `` 4K '' model with a resolution of 4096 × 2304 was released on October 13 , 2015 .