A storage unit in earlier iMac and Mac mini that combined a hard drive (HD) with a solid state drive (SSD). Introduced in 2012, the Fusion Drive automatically moves frequently used data from the ...

with 50-percent faster SSD speeds. The Fusion Drive is also standard on the highest-specification 21.5-inch iMac, with options for SSDs and 5400RPM hard drives also available for the screen size.

The Retina iMac can be further upgraded to a 4GHz quad-core Intel Core i7, 32GB of RAM a 3TB Fusion Drive or 1TB SSD and an AMD Radeon R9 M295X with 4GB of GDDR5 memory. Apple’s website explains the ...