This is really a confusing problem. For compatibility, the default speed of this memory in SPD is 1333. However when using XMP or manually setting the speed to 1600, something strange happens. If the PC is cold started, the system will be lagging all the time, especially when playing games. But if i restart the computer, everything goes well. I have disabled the c-states, updated the BIOS to F7, checked the diagnose led, changed the voltage of memory and cpu io, set the timing of the ram, but didn't work. How can i deal with it? Or it is a firmware problem?