Sapphire 7850 crashing on moderate OC

[alcatraz]

I'm using the latest Asus Tweak. It won't allow OC beyond 1050 gpu and 5400 memory, but that's irrelevant because the card won't even run at 1050/5200 at 1.15v. I'm leery of going much higher on the voltage. Am I being too conservative on the voltage? Tweak will allow me to take it to 1.222v. I want better performance but not at the expense of shortening the life of my card. Currently the only game I play is WoW, and unlike the last time I played (over a year ago), it's maxing the gpu in unpopulated areas of Pandaria (yes, I know Pandaria wasn't there a year ago, but I trust you know what I'm trying to say.) What happens you ask? Well, let me tell you. I'll be logged in, grinding away, and need to look something up. Alt+tab, maximize Firefox, and the main screen turns to rows of barbwire. Secondary monitor is fine, but loads of good that does me. As always, help is greatly appreciated.

Relevant system specs:
Asus P8P67 PRO
Cooler Master Hyper 212 cooler
i2500K @ 4.2/1.29v
16gig DDR3 Ripjaw, stock
750w psu
Cooler Master HAF 922
1st monitor: 26in Vizio HD TV
2nd monitor: decade old Gateway flatscreen

 

[maxinexus]

First I would go default on your CPU and then try to overclock your VGA. At stock voltage with (+20% power limit) try to reach the point when issues start to appear tune down 5-10Mhz and there is your final core clock at@stock voltage. If you want to push further go up with volts to 1.2v
Once you find the tipping point dial down 5-10Mhz them move on to memory overclock.

Once you have these set you can clock your CPU. If you have the option give your NB more juice as well.