manual turn off autoswitch GPU chip

Hi guys, i have big problem with my MacBook Pro Early 2011.

He is freezed during power up. Sometimes he showstriped screen display. I be sure this is problem with video chip or vedio switching.

In my city haven't service, and now i want turn off autocwitching video chip and always use 1 gpu chip.

On sys pref i turn off Autoswitch vedo chip, but it's turn on again(

Maybe have another way to turn off this function and always use 1 video chip?

Thanks.