A-Tech 16GB (2 x 8GB) RAM for Alienware X51 R2 | DDR3 1600MHz DIMM PC3-12800 240-Pin Non-ECC UDIMM Memory Upgrade Kit at Amazon.com
CMS 16GB (2X8GB) DDR3 12800 1600MHz Non ECC DIMM Memory Ram Upgrade Compatible with Alienware® X51 R2 Desktop - A63 at Amazon.com
Tried to upgrade the memory on new R11. Got the exact spec.. got two boots into Windows verified 32gb..and two boots with four blinking Alienware Yellows which says memory issue. Pulled the
8GB Memory Dell Alienware X51 R3 DDR4 RAM Upgrade
Dell Alienware X51 Desktop, Intel Core i7-4790, 8 GB memory, 2 TB Hard Drive*FREE UPGRADE TO WINDOWS 10 - Sam's Club