But CPU-Z displays the exact same value as the one the BIOS displays (after applying the manual value of 1.425). That's a bit too coincidental.
I've also run an OCCT test at 4 GHZ and failed it a few minutes in with a displayed Vcore of 1.38. I refuse to believe I can't hit 4 GHZ on 1.425V.
PS Motherboard is ASUS M5A97 R2.0.