My 3570k runs at 4400 with 1.26 Vcore
And BSOD x45 even with 1.28 vcore. Thing is according to CPU-Z vcore drops a lot when in Windows and under load. This is on z77-v Pro board and latest BIOS.

Cooling is H80 in well ventilated case (Antec 1200) and temps are not higher than 72C using Prime 27.6

Any ideas on what I could do to improve o/c?
What is a safe 24/7 Vcore for Ivys when using water?