According to the report posted at Reddit, by disabling Nvidia Streaming service, which usually starts-up automatically with Windows, users get a frame-rate increase of about 3 to 5 percent. While it is not a big number, in some situations it can mean the difference between a playable and unplayable game.
The aforementioned service is actually used for streaming games to the Nvidia Shield console so unless you own one, you actually will not be needing the nvstreamsvc.exe, at least not unless you enjoy a pointless performance drop. All you have to do is find the "NVIDIA Streamer Service" in Windows Services, by typing services.msc in Run, and disable it. Bear in mind that The service is also available for ShadowPlay feature, so you might need to start it up manually when you need it.
In any case, Nvidia Geforce users just a got a free performance boost and although minor, it is still a performance boost.