1.368 on the Vcore, dynamically boosting depending on system demand. It stays at 1.6GHz and 1.18Vcore unless it's stressed to more than 70% then it steadily overclocks to 5GHz at 100% stress. There are a few other voltage tweaks needed to get it stable at higher than 4.8GHz.
I've thrown 1.536V through this chip before and it didn't die. Great little overclocker.