I cannot run nfs hot pursuit 2010 at 20fps?

im using pentium d 3.00ghz ,2gb ram ,500gb hard disk and 1gb xfx geforce 9500gt ddr2..i cannot play nfs at even 20fps at 800x600 or 1024x768..i installed the latest patch but no use ..i dont want to upgrade my cpu as i dont have enough money ..I WANT TO RUN THIS GAME AT 20 FPS WITH THIS CPU IF ANY OPTIMISATION CAN BE DONE WITH THIS CPU PL TELL ME