try turning on vsync in your game this will limit the frames rendered saving power, heat, ext.
and of-course reduce "tearing".
also what "certain games" are we talking about? the integrated intel HD graphics aren't that powerful to begin with and are part of the CPU as an extension. are you saying these "certain games" worked fine before?
check your system for any resource hungry applications running in the background also scan for any malware/viruses and defrag your HDD unless your drive is a solid state that is.