How Much Memory Can I Put In A 2009 iMac?
The iMac was updated twice in 2009 - in March and in October. All the models from that year use 1066MHz DDR3 PC3-8500 SDRAM. However, the March 2009 iMac only has two memory slots (maximum 8GB total) while the October 2009 iMac has four memory slots (maximum 16GB total).
Before buying, you should always double-check to make sure that you are finding the info for your exact Mac model. App Sliced Memory can help you figure out which iMac is which when you visit our iMac memory section.
App Sliced Memory will also help you find the lowest price on compatible iMac RAM. We always recommend from one of the third-party sites we list since they are able to match Apple's quality at a fraction of the price.