Review on 🖥️ DUOMEIQI PC3-10600 DDR3 RAM 4GB 1333MHz – High Performance SODIMM for Laptops by Matthew Guiney

I have a late 2013 iMac. When I opened the memory port, the existing memory was in two slots with one open slot in between. I inserted new memory cards into the two open slots and the memory was not recognized. I removed the old memory and put the new memory in the same slots and it worked fine. I added old memory to two empty slots and had the full amount of memory combined. No documentation I could find said this would happen. If you are only adding to open slots and getting an error, follow the procedure above and it should work. That's why I gave 4 instead of 5 stars.