When I overclock my memory on the DX79SR motherboard (I use the XMP setting for the chips, 2133 and have newest bios) the board does not enter S3 sleep state and needs to be rebooted. Power button blinks like it is suppose to but computer does not shut down and continues to run until I reboot it. When I use the regular settings for the memory the board enters S3 like it is suppose to. Does this need a firmware update to fix? Any help would be appreciated.
Either a problem with your power supply not able to supply enough standby current for the over clocked memory, or it isn't stable enough to survive the transitions to lower refresh rates it sees in standby.
It is the cost of pushing things beyond their typical ratings.
To be honest given the extra latency you need to employ to drive the memory at 2133MHz it probably isn't giving you much real-world performance difference than running at 1600MHz but with lower latency.