Why is my 1333MHz memory downgraded to 1066MHz or 800MHz on the X8SAX, C7X58, X8ST3-F/E and X8STi main boards?
The memory controller is built in CPU instead of North Bridge on X58 chipset platforms. Please check your CPU Spec. If your CPU QPI is NOT 6.4GT/S, it may not support 1333MHz and memory speed may be downgraded. For more information, please visit www.intel.com.