weird thing happen to me also last night...
i updated my bios to the latest one... after the update is done reboot and everything.... i checked the bios for new option... got some new one but useless to me...
then i looked at the hardware monitoring option in bios .... the default vcore is now 1.325v instead of 1.275v as usual.... damn i tot this bios is just like the one making my censors crazy, set everything to default then boot to windows...
booting to windows ok no prob.... open biostar utilities both the hardware monitor and t-series oc 3 utilities and open cpu-z also....
cpu-z reading is the same as in bios the vcore default now has increased....
then i restart and went into bios and set everything to 3124MHz setup but i left the cpuVid and the vcore option at default cos with this clock my chip need only 1.31 volt.... bott back to windows and bla...bla..bla... orthos to stress test ... click the start button and..... Wallaaaaa....
BSOD on the spot.....
WTH..... reset cmos and return back to bios.... check back the hardware monitor and surprise the vcore has reduce too 1.25v from 1.325 at default....
set everything back to clock 3124MHz with 1.31Vcore....orthos failed after 1 min 18 sec....
so with a very

feeling i restart again and top up the vcore a notch....i did this a few times but still orthos failed....
then while i was setting the vcore my son came in the room and started hitting the keyboard..... bla...bla...bla.... accidently i dont know waht key was hit... but i boot into windows.....
open cpu-z and vcore 1.295V test with orthos passed 1 h 34 m ......
and yes this is a true story....
did u do a cold boot after made changes in bios. i faced this kinda problem when i was on 790gx2, especially when mingle w/ nb/htt multi.
we're almost d same batch lor...