64bit support will come to precision in September. Until then Afterburner has exclusivity.

@ 1in1class
 
Because the 500 series cards are "Fermi" cards, and 600 series are "Kepler" cards, they act a lot differently from each other.  A lot of the 600 series cards have locked voltages, so you may not be able to increase your voltage with the stock bios (firmware).
 
As far as making a 600 series card OC with PrecX like a 500 series card, that's not possible.  Fermi & Kepler cards are completely different animals.
 
The +13MHz you refer to, that's the increment the clock table is set at.  Meaning if you add +10 GPU offset, it won't increase, but +13 will up your clock speed by 13MHz.  Next increment would be +26 and so on.
 
The memory offset is different.  For the most part, you can increase this as you like.
 
Couple other things with the Kepler cards.  Usually when you reach about 70C, the card will auto downclock to maintain the temp.  Same for the power target, once you exceed 100%. the card will also throttle down some until the power is back under control.  Most people will just set the power target up to max to minimize the throttling down part.
 

1in1class
Wow I did not know this thank you. So before I open the card up, one more question. I know the card will go over 70c so for me to keep it at my OC speed so it don't down clock I can set it by power target? If I'm not able to keep it from down clocking I'm not going to open it.
 

I used to run two 670FTW's in SLI, and even while running graphically demanding games, my temps never exceeded 67C on either card.  Also, when I said it downclocks at 70C, it's only by 13 or maybe 26MHz.  As soon as the temp goes back under 70C, the clock speed will boost back up.
 
If you only have one card and halfway decent airflow in your case, it's pretty easy to stay under 70C.  Especially when using a custom fan profile in PrecX.
 
As far as the power target, you'll be able to simply and safely increase it from 100% to whatever the max percentage is for your card.  When I went from my 580's to my 670's, it took a little time & experimenting to get used to how they function compared to what I was used to.  But once I did, I prefer them to the older cards.
 
One other thing, whatever your factory spec shows for your boost clock speed, they almost always boost quite a bit higher when a load is put on the cards.  It does this automatically btw.

Same driver.

Is there a solution to precision x not saving over voltages? Even small over clocks on my 780ti classy arent stable without over voltage.

Thepackman99
I'm having exactly the same issue. I was able to get my GTX 780 ACX running stable at 133MHz above stock, but that required a fair voltage boost ( I'm ok with that). The problem I'm having now is Precision X 16 isn't applying my overvoltage settings, I've been through all of the settings to no avail. So until someone fixes this deal-breaker I'm using the old version. Also could there also be a fix for the lack of CUDA support when K-Boost is enabled? 

This is the Precision X 4.2.1 thread.  Precision X 16 is version 5.2.0 and has a totally recreated and different base code and therefore behaves nothing like version 4.2.1.
 
Please post in the appropriate thread.  Also, please look before asking the same question over and over again.  This bug has been reported countless times already and EVGA is aware of the issue.
http://forums.evga.com/Precision-X-15-and-16-Bug-Tracker-Thread-m2221067.aspx