gaming Upgrading to a GTX 770 4GB, is my PSU low?

[TheMarkz0ne 962]

I wanted to ask if my power supply can handle this card. Also if I need to overclock my i53570k to avoid bottle necking my rig. 

 

Asus P8Z77 V LX

Cooler master hyper 212+ CPU fan

GTX 660 2GB SLI(heat sink issues)

16 GB RAM DDR3 Corsair 

600 w corsair psu

2 HDDs, 3 TB(Windows 7) 1 TB(Ubuntu 13.10)

blu ray drive 

3 case fans

Haff 922 case

 

Also I noticed the 770 is not performing better than my GTX 660 for Arkham City...Why is that?

 

http://www.newegg.com/Product/Product.aspx?Item=N82E16814130948

Edited March 3, 2014 by TheMarkz0ne