Introduced in October 2009, the iMac (Late 2009) models had larger screens and faster processors than the previous iMac (Early 2009) line. The iMac (Late 2009) shipped in 4 configurations. Built-to-order options included up to 16 GB of RAM and a 2.8 GHz Intel Core i7 quad-core processor.
For a full list of technical specifications, see link:
https://support.apple.com/en-ca/112564