A-Tech 16GB Kit (4x4GB) DDR3 1066MHz PC3-8500 SODIMM 204-Pin Memory Upgrade for Apple iMac Late 2009

16GB DDR3 Kit for Late 2009 iMac

This kit provides four 4GB SO-DIMM modules for a total of 16GB of DDR3 1066MHz memory. It is built for the 21.5-inch and 27-inch iMac models released in late 2009, matching the factory PC3-8500 specification. The unbuffered, non-ECC design fits the standard SO-DIMM slots used in these all-in-one desktops. Users restoring or upgrading these specific machines will find the correct form factor and voltage.

204-Pin SO-DIMM Build and Daily Use

Each module uses a 204-pin SO-DIMM edge connector without a heat spreader, keeping the profile low enough for the tight iMac memory bay. Major-brand chips are used throughout, and every stick is tested before shipping. The 1.50V operating voltage matches the original Apple requirement, so the system recognises the memory without manual configuration. Installation follows the standard hatch process on the back of the iMac chassis.

DDR3 1066MHz Practical Limits

The PC3-8500 interface caps bandwidth at the DDR3 1066MHz data rate, so heavier workloads will hit a throughput ceiling regardless of capacity. Four ranks of 2Rx8 organisation fill all available slots on these iMacs, leaving no room for further expansion. The kit does not support ECC or registered operation, so it cannot be used in workstations or servers that require those features. Buyers needing higher speeds or larger total memory must move to a newer platform.