A story is making the rounds that disabling the NVIDIA Streamer Service can increase your framerate in games by 3-5 percent. The Streamer Service is only used by NVIDIA's Shield device so if you don't have this console there's no reason why it should be running. Details on how to disable it can be found at Reddit.
Legit Reviews contacted NVIDIA about this issue and got to hear they're aware that a small number of systems are affected by this and that it will be fixed in an update for GeForce Experience that will be coming out in May.
The site adds that AMD Radeon users can check if External Events Utility or Fuel Service are running, disabling these can give a small performance bump as well. While External Events is pretty useless, it allows you to use hotkeys for Catalyst control panel features, disabling the Fuel Service isn't really recommended. AMD's Fuel Service is used for some of the performance and power features in the Catalyst Control Panel, including the AMD OverDrive feature.
If you manually install your driver and do a custom install you might have already have this service disabled! AMD Radeon users might be laughing right now, but keep in mind AMD users can disable the AMD External Events Utility and AMD FUEL Service for a small performance bump as well. If you want the most performance that is possible there is usually always something you can disable to give you an extra percent or two!