Older versions of the Source engine, such as the 2007 SDK Base, will go into a sort of hibernation mode when the game window is not active for a while. It takes a minute to switch back to the game, but while in hibernation mode it frees up system resources for other stuff.
The new version of the engine (2013 SDK Base) never goes into hibernation mode. I need to get it to do that again. Does anybody have some advice on where I might start looking in the code?
By the way, I am working with the Multiplayer branches of each of the engines.