Also, what's up with people getting good results on their 780s using T/Z12x24 ? I get absolutely craptastic results with that!
That's like the 15x24 for some 780ti... yes me too I'd be curious to know... Is there different models (beside factory bios) ?
This is due to the new Titan kernel that the Nvidia engineer submitted. S/He stated that the best config for it will be SMX x 24. This is why this setting is preferred.
780 -l T12x24
Titan -l T14x24
780Ti -l T15x24
Please try all -H -C and -m settings before you write the changes off. This is KEY with this release.
I went from
-l Z14x24 -H 1 -C 1 -m 2
over to
-l T14x24 -H 1 -C 0 -m 0
(commit 114 to release) saw a very little kh/s change but found that the core could stably OC another 50MHz improving kh/s due to more OC head room

No matter what combination I use, the best I can get with T12x24 for my 780 is less than 1/3 of T12x20, ~170-185kh/s depending on settings.