AMD Phenom II(tm) 830 2.8 GHz 6 GB DDR3 RAM at 2000.0 MHz FOXCONN Model 2AB1 MOBO 750 GB SATA 3.0 Gb/sec 7200 RPM HDD 250W Power Supply(I'm ugrading this to a 650W)
Current Graphics Card: ATI Radeon HD 4200
More aboutneed bottleneck
no, your system will do fine, and you will notice a great upgrade from what you have n.n
You are good. The 7770 only needs about 430W, but there is no harm in overprovisioning. Whatever you do, make that new psu a quality unit. Antec, Seasonic, Corsair, XFX, and PC P&C should be safe buys.
If you don't already have the 650w PSU I would recommend going with a smaller one on your system even if you where running two 7770's factory specs would still only call for about a 550w those 7770's don't draw much juice.Your rig will be fine though regardless.
increase AA and set texture details higher. If you get same fps, cpu is bottleneck. If fps drops, gpu is bottleneck.