It is preloaded from the factory with two 1GB or 2GB DDR3-1066. Mac Mini Early to Late 2009, Late 2009 Server It is preloaded from the factory with two 1GB or 2GB DDR3-1066 SO-DIMMs.
The Mid 2010 Mac Mini has two memory slots. It is preloaded from the factory with two 1GB. The Mac Mini Model IDs 5,1 through 5,3 have two memory slots. Mac Mini Memory for Models 5.1 5.2 and 5.3 It is preloaded from the factory with two 2GB DDR3 SO-DIMMs. The Late 2012 Mac Mini has two memory slots. It is preloaded from the factory with two 4GB 2666MHz DDR4 PC4-21300 SO-DIMMs. The Late 2018 Mac Mini has two memory slots.