i downloaded the benchmark
but the benchmark alwyis chooses the intel graphic card , i have Geforce 660m GTX ( 2GB )
i tried to run the software in Nvidia control panel and chosen the high performer graphic card
but the same message appear
Because of how Nvidia Optimus works, it will always say the Intel integrated graphics. My laptop is the same way. You can be certain it's using the Nvidia GPU if the score is higher than when you actually use the Intel IGP.
Long, boring explanation:
The way Nvidia Optimus works is that the Intel IGP always active in Optimus setups. The Intel IGP is always what is really outputting the video, which is why it is always detected by software which doesn't understand Optimus. Most software doesn't understand Optimus. The Nvidia GPU, when active, actually directly renders into the IGP's framebuffer when rendering a scene, but the IGP is still outputting the video signal. It is otherwise set in a low-power state, which is why Optimus saves the battery when the Nvidia GPU isn't actually doing anything. All of this occurs on a low level in hardware, which is why it's invisible to software detecting your GPU like the benchmark.
Nvidia Optimus is really quite clever when you think about it, as it bypasses the problem with older Switchable Graphics designs where you had to switch the entire active GPU from one to another, which typically disrupted every application running on the screen and often was disruptive for the OS as well. MS had so many problems with Windows machines that used these designs that starting with Windows 7 they altered the Windows Graphics Foundation so that drivers were allowed to be simultaneously active at all times for graphics cards, which is why Switchable Graphics was deprecated and replaced by Nvidia Optimus and AMD Enduro.
It was also a huge problem for driver updates on laptops which used Switchable Graphics because they required special drivers from the OEMs and we all know how good laptop manufacturers are with driver updates. You couldn't just use any drivers and expect them to work. Optimus requires no special drivers as it works on a hardware level, so you can keep your Intel and Nvidia graphic drivers updated all the time separately and it won't affect Optimus's function.