This GeIL DDR3 Series laptop memory module operates at 1066MHz, which is the default speed in many early-release DDR3 laptops, including many MacBook and MacBook Pro computers. It is generally recommended to match the speed of any memory upgrade with the speed of the original memory in the system. This makes upgrading the memory much easier and requires less (if any) configuration.
4GB DDR3 1333MHz laptop memory module, this memory is suitable for laptops using DDR3 memory. Speed rating of PC3-8500 and memory timings of CL7 (7-7-7-20) at 1.5V.
This 4GB laptop memory module is ideal if you are removing existing 512MB or 1GB modules from your system, and wanting to get the most out of your laptop. Adding more memory will help improve the performance of your system, while shortening the time it takes to boot up.
For compatibility please refer to the notebook manufacturer handbook prior to purchasing this memory upgrade.