I have an ATI Radeon x1600 pro graphics card and every time i turn on my computer the fan runs really fast then after about 3 seconds slows down. Why does this happen? Is this because the graphics card isn't running at it's potential at all times? If so can i over clock it? would i need better cooling? With some new game updates later i have had to reduce my graphics properties so they won't lag. Just wondering if there is something i can do to improve my graphics, without buying a new card.