12GB Total memory using 3PC 4GB 1066MHz Module 240pin dimm DDR3 8500. This module is non ecc. pc1333 will work as well. 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. Compatible with: ASUS/ASmobile P6 Motherboard P6T ASUS/ASmobile P6 Motherboard P6T Deluxe ASUS/ASmobile P6 Motherboard P6T SE Max Memory: 24 GB Socekts: 6 Sockets (2 Banks of 3) MODULES MUST BE ORDERED AND INSTALLED IN GROUPS OF THREE for Triple Channel mode. MODULES MUST BE ORDERED AND INSTALLED IN PAIRS for Dual Channel mode. If 4GB is installed, the recognized memory may be reduced to 3.5GB or less (depending on system configuration and memory allocation). A 64-bit Operating System is required to utilize more than 4GB of memory. Per ASUS, Intel XMP and DDR3-1600 or higher speed is supported in one DIMM per channel only.