| iMac (17-inch and 20-inch, Early 2006) iMac4,1 | 2 DDR2 SO-DIMM slots | 2 GB | Upgradable | 8 |
| iMac (17-inch and 20-inch, Late 2006) iMac5,1 | 2 DDR2 SO-DIMM slots | 4 GB | Upgradable | 28 |
| iMac (17-inch, Late 2006 CD) iMac5,2 | 2 DDR2 SO-DIMM slots | 2 GB | Upgradable | 5 |
| iMac (20-inch and 24-inch, Early 2008) iMac8,1 | 2 DDR2 SO-DIMM slots | 6 GB | Upgradable | 120 |
| iMac (20-inch and 24-inch, Early and Mid 2009) iMac9,1 | 2 DDR3 SO-DIMM slots | 8 GB | Upgradable | 97 |
| iMac (20-inch and 24-inch, Mid 2007) iMac7,1 | 2 DDR2 SO-DIMM slots | 6 GB | Upgradable | 124 |
| iMac (21.5-inch and 27-inch, Late 2009) iMac10,1 | 4 DDR3 SO-DIMM slots | 16 GB | Upgradable | 113 |
| iMac (21.5-inch, 2017) iMac18,1 | 2 DDR4 SO-DIMM slots | 16 GB | Upgradable | 21 |
| iMac (21.5-inch, Late 2012) iMac13,1 | 2 DDR3 SO-DIMM slots | 16 GB | Upgradable | 48 |
| iMac (21.5-inch, Late 2013, GeForce graphics) iMac14,3 | 2 DDR3 SO-DIMM slots | 16 GB | Upgradable | 24 |
| iMac (21.5-inch, Late 2013) iMac14,1 | 2 DDR3 SO-DIMM slots | 16 GB | Upgradable | 59 |
| iMac (21.5-inch, Late 2015) iMac16,1 | Soldered, no slot | | Not upgradable | 12 |
| iMac (21.5-inch, Mid 2010) iMac11,2 | 4 DDR3 SO-DIMM slots | 16 GB | Upgradable | 57 |
| iMac (21.5-inch, Mid 2011) iMac12,1 | 4 DDR3 SO-DIMM slots | 32 GB | Upgradable | 154 |
| iMac (21.5-inch, Mid 2014) iMac14,4 | Soldered, no slot | | Not upgradable | 26 |
| iMac (24-inch, Late 2006) iMac6,1 | 2 DDR2 SO-DIMM slots | 4 GB | Upgradable | 5 |
| iMac (27-inch, Late 2009, Core i5 and i7) iMac11,1 | 4 DDR3 SO-DIMM slots | 16 GB | Upgradable | 40 |
| iMac (27-inch, Late 2012) iMac13,2 | 4 DDR3 SO-DIMM slots | 24 GB | Upgradable | 38 |
| iMac (27-inch, Late 2013) iMac14,2 | 4 DDR3 SO-DIMM slots | 32 GB | Upgradable | 79 |
| iMac (27-inch, Mid 2010) iMac11,3 | 4 DDR3 SO-DIMM slots | 20 GB | Upgradable | 54 |
| iMac (27-inch, Mid 2011) iMac12,2 | 4 DDR3 SO-DIMM slots | 32 GB | Upgradable | 136 |
| iMac (Retina 4K, 21.5-inch, 2017) iMac18,2 | 2 DDR4 SO-DIMM slots | 32 GB | Upgradable | 55 |
| iMac (Retina 4K, 21.5-inch, 2019) iMac19,2 | 2 DDR4 SO-DIMM slots | 32 GB | Upgradable | 41 |
| iMac (Retina 4K, 21.5-inch, Late 2015) iMac16,2 | Soldered, no slot | | Not upgradable | 44 |
| iMac (Retina 5K, 27-inch, 2017) iMac18,3 | 4 DDR4 SO-DIMM slots | 64 GB | Upgradable | 57 |
| iMac (Retina 5K, 27-inch, 2019) iMac19,1 | 4 DDR4 SO-DIMM slots | 64 GB | Upgradable | 38 |
| iMac (Retina 5K, 27-inch, 2020) iMac20,1 | 4 DDR4 SO-DIMM slots | 32 GB | Upgradable | 2 |
| iMac (Retina 5K, 27-inch, Late 2014 and Mid 2015) iMac15,1 | 4 DDR3 SO-DIMM slots | 32 GB | Upgradable | 24 |
| iMac (Retina 5K, 27-inch, Late 2015) iMac17,1 | 4 DDR3 SO-DIMM slots | 32 GB | Upgradable | 50 |