Yes, it will be enough. The GTX650Ti has a single 6-pin PCIe cable. To remain in spec, it can draw no more than 150W (75W from the mobo and 75W from that cable). It actually only draws up to 110W (running flat out), leaving 290W for the rest of your system. You're good to go.
Ok... I was little worried and on tight budget...didn't wanted to compromise on seasonic since I believe its best quality ....Thanks