"GPU 1G" is not enough info. Having 1 GB of video RAM does not mean it's blazing fast. Provide manuracturer and model number and we'll talk. Also, Intel Core i3 is a low-end processor. I guess it will manage, but forget about 60 fps.CPU. Intel i3 3.3ghs
There is a Dual-core NVidia GPU 1200 mhz 2.0 GB of VRAM.But i don't remember seeing one with 3,0 ghz clock speed.you have a 3 ghz Gpu ? seriously? What planet are you on? The top of the line from nvidia is like 1215 mhz.
Anyways, no you dont need a 3 ghz GPU, trust me. second, I do agree a i5 will help but you can't just go swamping chips here. Everything on that board will have to change.