Created on: April 29, 2013
Last updated: April 19, 2022
Generally, any iMac, non-Retina MacBook, or non-Retina MacBook Pro, or Mac Mini from the last several years should allow RAM modules of the same spec but different capacities to be installed in any of the RAM slots in the computer. There is no specific order or "stacking" of capacities required.
Some Mac Pro models do require the user to pair RAM modules of different capacities in specific ways. Please check the Apple user manual for your specific Mac Pro to get the most accurate information – some manuals contain a diagram that shows how to group the RAM modules for the best performance.