V core on GA-EP45-DQ6

Hello all.I got an E8400 oc to 4.1Ghz.I would like to push it more but i dont want to exceed safe voltage which is 1.3625V .The fact is that in my overclocking options in bios i have Vcore set as 1.3625V BUT CPU-Z reports Core Voltage 1.328V.When i set Vcore in bios at 1.405 CPU-Z reports 1.360V.Why is that?Thanks for your time

thats due to vdroop, you can read more about it here
http://www.thetechrepository.com/showthread.php?t=126
http://www.anandtech.com/cpuchipsets/intel/showdoc.aspx?i=3184&p=5

Just increase the Vcore by .04v to compensate. And 1.3625v is only the "recommended" maximum Vcore, while 1.45v is the "absolute" maximum. So depending on your cooling situation and core temp's under load, Vcore can be increased past the recommended maximum voltage setting of 1.3625v