I have searched years ago, and recently, and come across this thread: https://forums.macrumors.com/threads/can-you-put-32gb-in-a-macbook-pro-9-1.1736888/ I also have a MacBook Pro 9,1 and I'm interested in revisiting this topic, in light of new hardware. At the time, the stated issue in that thread was that there were no 16 GB RAM modules on the market. As there are only 2 slots, you would need 2x16 GB to get 32 GB total. There is now a 16 GB RAM module that should fit this MBP though: http://www.crucial.com/usa/en/ct204864bf160b And there are more companies (though not many) that also manufacture them: https://www.newegg.com/Product/ProductList.aspx?Description=16GB 1600MHz DDR3L SDRAM&Submit=ENE&IsNodeId=1&N=100007609 600000279 601275424 600559388 600006178 According to Intel, for the processors included with this model, i7-3820QM, i7-3720QM, i7-3615QM, all of them are capable of supporting 32 GB of memory. However, I can't find any reports of anyone trying it at all. I've found talk here and there that the slots are limited to 8 GB each, but I can't find any technical information that confirms this. I'm not able to find any actual technical reason as to why it shouldn't work. But Apple does claim the maximum memory for this model is 16 GB. I'd like to know for sure before I pull the trigger on $300 of memory. But maybe someone else would like to try it out with this new memory that's available today?