In the end my results on this chip are mediocre.
I can get it to pass Aida64 stress test easily at 4.5GHz but will fail IBT and Prime95. Heat is not the issue either as according to Real temp I am 15-20 Celsius away from TJMAX.
I am pretty stringent when it comes to OC testing. I know a lot of people online will pass a couple of hours Aida64 and say its stable. And months down the road will say "I've never had any problems on my computer" though they don't remember that one time a game didn't load on the first try, or their internet browser crashed randomly, or that time they booted into windows and their shortcut icons didn't load the little pictures until they refreshed the desktop, never thinking the overclock might be related.
Its sad to say that everyone has a different version of stable, and maybe people who say they have stable systems might actually not. Or say its stable initially and never come back to report on any changes. I think this community is a little better for that at least.
Anyway, for my 1680V2
I was able to Pass
IBT Burn test on MAXIMUM using 60GB RAM for 30 Runs (took around 22HRS)
Prime 95 24HRS
and Aida64 24 Hrs
On my Rampage IV Black Edition
at 4.4GHz (105BCLK X 42 Multp)
with 1.28 Set on the VCore in Bios (netting 1.29 Being bulled under full load with LLC set to auto).
Even though my temps are fine Trying to run IBT or P95 with Vcore set to anything above 1.30 will result in system restart. Seems like it'd be heat related but monitoring everything through Aida64 and Real temp, all my thermals seem fine.
Just playing games, or running Cinebench is fine at that voltage though. Probably because as well all know P95 and IBT TRULY fully stress the system while general usage does not most of the time.
In the end I kind of regret upgrading from my Xeon E5-2687W v2 since I was able to overclock that to 4.1GHz already at 1.24VCore, the extra 300MHz wasnt worth the extra money. To each their own though