my system specs:
3770k-3.6ghz(turbo 4.2 i guess)
hdd:barracuda 7200rpm 1tb
gpu:7970 sapphire dual-x oc 1460/1060
psu:cooler master thunder 700 watts(later got to know cooler master isn't a great brand )(but had no problems with it ,had been monitoring it daily -all the rails 12v,5v,3.3v using asus ai suite ,gpu z and many other softwares ,its always constant; its been nearly 3 months since i assembled this system .it has a 12 v rail at 55Amps)
four 120m fans and one 200m
everything running fine but sorta feeling held up by 7970 ,not sure ;its a good card crysis 3 at smaa 2x or metro last light at smaa 0.5x no problems at 1080p .but,i want that feeling where there is no restriction turning everthying up ,and also thinking of adding one more display ,many new titles are yet to launch i don't want to see any hicups whatsoever ! so waiting for your opinions guys.....
Since you want to turn everything up, I'll think you'll be happy with the PhysX in Metro Last Light on a GTX 690.
The GTX 690 requires 38 Amps, so you should be fine. More from Legit Reviews:
"The NVIDIA GeForce GTX 690 video card requires a 650 Watt or greater power supply with a minimum of 38 Amps on the +12V rail and two 6-pin PCI Express power connectors for proper connection. It should be noted that the NVIDIA minimum system power requirement is based on a PC configured with an Intel Core i7 3.2GHz CPU. These are pretty reasonable power requirements, so that is good news for everyone!" http://www.legitreviews.com/article/1921/2/