Yes, there's something wrong either with your settings or your computer. A DxDiag output will help to see if there's something wrong with your hardware, drivers etc. If the i5 is even near the 3 GHz range you should be able to max everything except the Environment Map slider and still get a solid 60 FPS.
Possible explanations for your poor performance: No dedicated motherboard drivers installed, video card settings maxxed in the Nvidia control panel, Environment Map maxxed, Windows Update eating half of your processor cycles...