M15X FREEZING PROBLEM/UPGRADING GRAPHICS CARD

My M15x has been freezing during gaming lately, i only get about 5-10 mins into the game until it freezes completely and requires a manual shutdown. Its not the temp cuz i checked, sometimes it doesn't freeze and i can game for hours but it doesn't happen often. In light of this freezing problem iv decided to upgrade my graphics card so can someone suggest the best compatible graphics card for my laptop(if upgrading is even possible). I'v read that the 460m is compatible but i wanna know if the fans will be able to cool it or if the power will be sufficient.