Recently I have purchased Kingston hyperx 1866mhz memory of 16Gb. For the Asus g74sx-xr1. The system properties is showing 16GB but still it is running at the 1333mhz. CPU-Z installed on the system DRAM frequency at 665.3mhz. Let me know any of the forum user has managed to install RAM on the laptop of yours. I am waiting for the prompt replies of yours. Thanks a lot in advance.