I think with a better processor you should be able to achieve atleast 20-30fps in most games on medium settings, in some games on High Settings. Its just that "our" graphics card is only 64bit instead of 128bit or higher but that should not make that much of a difference.
my specs are: Athlon X4 860K 4x4GHz, 16GB Ram, 4GB Gainward GT730 GDDR5, 450w psu, a 1tb HDD and 64bit Windows 7 Ultimate. As stated in my first Topic, I get stable 40-50FPS and sometimes even 60FPS in GTA5 on High Settings.