A-Tech 8GB Kit (4x2GB) DDR3 1066MHz PC3-8500 SODIMM 204-Pin Memory Upgrade

Apple iMac Late 2009 memory kit

This 8 GB DDR3 kit contains four 2 GB SO-DIMM modules built for the 21.5-inch and 27-inch iMac models released in late 2009. It matches the factory PC3-8500 specification and uses unbuffered non-ECC chips. The modules install directly into the four SO-DIMM slots on those systems.

Low-voltage DDR3 operation

Each module runs at the standard 1.50 V DDR3 voltage with no heat spreader required. The JEDEC 1066 MHz rating keeps power draw modest and the memory controller cool during typical desktop workloads. Silent operation is maintained because the iMac's internal airflow handles the thermal load.

Sustained multitasking headroom

Filling all four slots with matched 2 GB modules lets the memory controller run in interleaved mode for consistent bandwidth under long rendering or virtualisation sessions. The kit is validated for the iMac10,1 and iMac11,1 model identifiers and Apple order numbers MB950LL/A, MB952LL/A, MB953LL/A and MC507LL/A. Systems needing more than 8 GB or a different DDR generation cannot use this kit.