The MacBook Pro is built with the Intel-based Processor. It has two memory sockets and can be upgraded to 2-8GBs maximum depending on your model. Memory can be installed one module at a time. Apple recommends that two modules of the same size be installed for maximum performance.

Model Standard Memory Maximum Memory Memory Expansion Memory Sizes Memory Type
A1278 2GB/4GB 8GB Two Slots 2GB | 4GB 1066MHz PC3-8500 DDR3
A1278 (Early 2011 and later) 4GB (2GBx2) 8GB Two Slots 2GB | 4GB 1333MHz PC3-10600 DDR3