So I bought a laptop with switchable graphics. It has the Intel HD 4000 and a Radeon 7670m for its graphics. I don't know what graphics card it uses. When I set the graphics setting into high performance and play a game it lags but if I set it to power saving it doesn't. After about five minutes in a game (graphics settings set to power saving) it lags. How can I know what the laptop uses? And how do I get rid of the lag? My laptop is an HP g6 2091ex with an i7-3612QM and 6GB of RAM. OS is window 8 64 bit.