I bought a Lenovo Y580 laptop few days ago, this model is equipped with GTX 660m graphics card. However, the game performance is unbelievably poor since it out from the box. I realized there is something wrong with this graphics card. I downloaded GPU-z, and did a simple test. And I was shocked by the fact that my GTX 660m graphics card is running at 135.0mhz core clock. (It should be 835mhz at least!) Even the integrated graphics card "Intel HD graphics 4000" can run at 650mhz. Further examining showed that in the first few seconds GTX 660m was actually running at 835mhz, however the core temperature quickly reached 90+°C and the clock (maybe) automatically drop to 135.0mhz. This is very strange. Anyone has any idea what's going on here?