Best Buy: Alienware X51 Desktop Intel Core i7 8GB Memory 1TB Hard Drive AX51R2-5722BK
Alienware X51 R1 - 1600MHz RAM running at 1333Mhz - Dell Community
Alienware X51 R2 – Specs and upgrade options
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
CMS 32GB (4X8GB) DDR4 17000 2133MHz Non ECC DIMM Memory Ram Upgrade Compatible with Alienware® X51 R3 - C62 at Amazon.com
CMS 16GB (2X8GB) DDR4 17000 2133MHz NON ECC DIMM Memory Ram Upgrade Compatible with Alienware® x51 R3 - B107 System Specific Memory - Newegg.com