Just an update with my OCing (re: evga 780 SC (non-acx))
Seems like my core doesn't like anything above +90, even with all 3 extra voltage increments. Heat is not an issue as 85% fan speed keeps temps below 70c. Beyond that, memory goes as far as +225 before performance numbers start dropping. I reduced the memory to +150 as the performance gain between that and 225 seems negligible.
A little disappointed that voltage doesn't help increase core but can't really complain. Already at or above titan performance.
FYI for you or anyone else in this thread posting offset numbers, please don't do that, its meaningless when comparing different model cards. One card may have a base boost clock of 900 and another with 1000 so +90 offset doesn't tell me much when you're comparing boost clocks on two different cards. All that matters is your final boost clock speed which can measure under load. Offsets values are irrelevent and not useful.