Asus Probe reads 68~69 degrees so that would be at least 75c + at the core.
It's considering on the hotter side even for quad cores. But keep in mind that ambient temp is also a very important role here considering he's testing 4Ghz on air with a Tuniq Tower 120. I'm preety certain that his location is in Taiwan by looking at his language version os XP in Tranditional Chinese so ambient temp over there is at least 30+ degrees 24/7. Even in western Canada here, the temp during the day gets up to 29 degrees and 22 degrees by midnight. My Thermalright Ultra 120 Extreme is having a hard timing keeping my E6700 at ~3760mhz and my Orthos isn't 8+ hours stables now for some reasons...

I also presume that both of his Tuniq Tower 120 and the E6850 IHS aren't lapped so thus higher temps than what you'll see from some lapped results.