4GB Total memory using 1pc of 4GB 12800MHz Module 240pin dimm DDR3 1600mhz. This Motherboard can use either 10600 1333mhz or 12800 1600mhz or 8500 1066mhz Genuine CMS brand, CMS is one of the most trusted names in the Computer Memory industry and this product carries a Lifetime Warranty from CMS. MAX MEMORY 32GB SOCKETS 4 COMPATIBLE WITH Gigabyte GA-Z77X-UD5H, GA-Z77X-UD5H-WB WIFI Motherboard