![iMac "Core 2 Duo" 3.06 21.5" (Late 2009) Specs (Late 2009, MB950LL/A*, iMac10,1, A1311, 2308): EveryMac.com iMac "Core 2 Duo" 3.06 21.5" (Late 2009) Specs (Late 2009, MB950LL/A*, iMac10,1, A1311, 2308): EveryMac.com](https://everymac.com/images/cpu_pictures/apple-imac-al-21-late-2009.jpg)
iMac "Core 2 Duo" 3.06 21.5" (Late 2009) Specs (Late 2009, MB950LL/A*, iMac10,1, A1311, 2308): EveryMac.com
![A-Tech 4GB PC3-8500 DDR3 1066/1067 MHz RAM for MacBook, MacBook Pro, iMac, Mac Mini (Late 2008, Early/Mid/Late 2009, Mid 2010) | 204-Pin SODIMM Memory Upgrade Module at Amazon.com A-Tech 4GB PC3-8500 DDR3 1066/1067 MHz RAM for MacBook, MacBook Pro, iMac, Mac Mini (Late 2008, Early/Mid/Late 2009, Mid 2010) | 204-Pin SODIMM Memory Upgrade Module at Amazon.com](https://m.media-amazon.com/images/I/81aQlNZKt0L._AC_UF894,1000_QL80_.jpg)
A-Tech 4GB PC3-8500 DDR3 1066/1067 MHz RAM for MacBook, MacBook Pro, iMac, Mac Mini (Late 2008, Early/Mid/Late 2009, Mid 2010) | 204-Pin SODIMM Memory Upgrade Module at Amazon.com
![OWC 6GB (2GB + 4GB) PC8500 DDR3 1066MHz SO-DIMMs Memory Compatible with Late 2008, Early 2009, Early 2010 MacBook, MacBook Pro Unibody Models, 2009/2010 Mac Mini, 2009 iMac Models at Amazon.com OWC 6GB (2GB + 4GB) PC8500 DDR3 1066MHz SO-DIMMs Memory Compatible with Late 2008, Early 2009, Early 2010 MacBook, MacBook Pro Unibody Models, 2009/2010 Mac Mini, 2009 iMac Models at Amazon.com](https://m.media-amazon.com/images/I/81nVQGHArTS.jpg)
OWC 6GB (2GB + 4GB) PC8500 DDR3 1066MHz SO-DIMMs Memory Compatible with Late 2008, Early 2009, Early 2010 MacBook, MacBook Pro Unibody Models, 2009/2010 Mac Mini, 2009 iMac Models at Amazon.com
![Catalina 10.15.3 running decent on my mid 2009 iMac. Gonna max out the RAM to 8GB. 🤗 : r/CatalinaPatcher Catalina 10.15.3 running decent on my mid 2009 iMac. Gonna max out the RAM to 8GB. 🤗 : r/CatalinaPatcher](https://preview.redd.it/aqu0f6uoroo41.jpg?auto=webp&s=4c252b6db1a944eb16f06071ca37e5bcd7e4e10b)
Catalina 10.15.3 running decent on my mid 2009 iMac. Gonna max out the RAM to 8GB. 🤗 : r/CatalinaPatcher
![How to upgrade the memory of a 27-inch iMac with Retina 5K display (Late 2014 - Mid 2015) iMac15,1 - YouTube How to upgrade the memory of a 27-inch iMac with Retina 5K display (Late 2014 - Mid 2015) iMac15,1 - YouTube](https://i.ytimg.com/vi/1nQp_Yb8YW0/maxresdefault.jpg)