Product details
661-6503 4GB Memory, SODIMM, DDR3,1600 rpm, A1286 for Macbook Pro NB-5574W
This is a 4GB PC3-12800 SODIMM memory stick. This is not officially supported by any Apple models until the 2012 updates. The 2011 quad-core models with the Sandy Bridge processors do detect the higher speed.
Apple part number: 661-6503
Compatible models: A1286
661-6503 4GB Memory, SODIMM, DDR3,1600 rpm, A1286 for Macbook Pro
This is a 4GB PC3-12800 SODIMM memory stick. This is not officially supported by any Apple models until the 2012 updates. The 2011 quad-core models with the Sandy Bridge processors do detect the higher speed.
Apple part number: 661-6503
Compatible models: A1286
661-6503 4GB Memory, SODIMM, DDR3,1600 rpm, A1286 for Macbook Pro