Please help! Overclocking 2 EVGA SC GTX780's in SLi

[3minence]

Hello,

My main questions are:

-Should I only adjust one setting at a time? That is to say should I only overclock the core and leave the memory? / Do I need to overclock memory at all?
-If I require higher voltage will +25mV hurt my cards' lifespan, or is it negligible?

I have been attempting to boost my core clock on my EVGA GTX780's from the EVGA superclock of 967 to at least 1100. I should mention before I start that both cards are water-cooled, the hottest I have seen them is 60C after 2 hours of 'Furmark' 1080p Burn In. I also have a 1200W PSU so I don't have a power shortage. (EDIT: I also have a 144hz 1080p monitor, so I assure you, I do have a practical use for overclocking)

So I have installed EVGA's precision X and read a few guides and forums about how to go about overclocking, however I cannot seem to find a stable setting anywhere. The closest I have been to my goal was:

+80Mhz core (1047Mhz)
+160Mhz mem (1662Mhz(6648Mhz Effective))
106% GPU power
+13mV

This ran stable on Furmark burn-in for 2hrs (58C) and passed 3D Mark's Firestrike benchmark.
My system later crashed, in the same fashion as when I failed higher clock speed stability tests, when playing BF4 after a couple of hours.

Thankyou in advance.

Specs:
Intel i7 3930K @4.3Ghz (stable in prime 95 5hrs)
AsRock X79 Extreme9
Corsair Dominator Platinum 4x4Gb 2400Mhz
Mushkin Scorpion Deluxe 480GB
1200W Strider Evolution gold
2x EVGA SC GTX780 Sli
Asus VG248QE 1080p 27" 144hz

 

[3minence]

bump =/

 

[Powerbolt]

First off I'd like to say holy shit to your PSU and graphics setup. I'm partially jealous.

Voltage is tricky. As long as your temperatures remain within normal limits, and the voltage setting isn't blatantly outrageous. I don't think you'll have a problem with the life of the cards. I would suggest perhaps bumping them up a little at a time and monitor the cards closely. If it acts like it's getting more stable then you're at least moving in the right direction.

Here's a thread that might shed a little light on some normal, and max voltage ratings for the EVGA GTX 780 cards. http://forums.evga.com/tm.aspx?m=1945998

Best of luck.