G.Skill Trident Z NEO Series 32GB (2 x 16GB) 288-Pin SDRAM DDR4 4000 (PC4-32000) CL18-22-22-42 1.40V Dual Channel Desktop Memory Model F4-4000C18D-32GTZN at Amazon.com
64gb ram kit | Newegg.com
Amazon.com: CORSAIR VENGEANCE RGB PRO 16GB (2x8GB) DDR4 4000MHz C19 LED Desktop Memory - Black : Everything Else
G.SKILL 64GB (8 x 8GB) Ripjaws V Series PC4 32000 4000MHz 288-Pin SDRAM DDR4 Desktop Memory Model F4-4000C15Q2-64GVK at Amazon.com