When I hear for this I increased RailWorks performance (almost twice more fps) and other programs, or Windows in general. I set it on three desktop computers including mine. They all had a default power saving mode. This is the guide for Windows 8.1 but I think it is similar to the earlier version. Please note that it will likely increased electricity consumption. I hope not too much
Right click on the desktop and then as follows: Personalize -> Screen Saver -> Change power settings -> High performance -> Change plan settings -> Change advanced power settings
