Earlier this month, Microsoft confirmed that the Windows 10 Creators Update coming later this year would include a new feature called "Game Mode."
Redmond is still being a bit coy about precisely what Game Mode will and won't do, but the picture has become a little clearer. We spoke to Kevin Gammill, partner group program manager for the Xbox platform, about what Game Mode was for and what to expect. The overarching goal is to make Windows 10 "the best operating system for games"—and critically, to make it more consistent, so that frame rates and performance are more predictable and uniform. Gamill said that when Game Mode is active, the operating system will tend to be biased toward allocating CPU and GPU resources to the game.
Gammill didn't say this (and probably for good reason; there are segments of the PC gaming community that would regard the following as dirty words), but it sounds to us like the aim is to make PC gaming a little more, well, console-like. Console hardware is much more predictable than PC hardware, with developers knowing exactly how many processor cores and GPU shaders, and how much system memory, they'll have access to at any moment. Game Mode won't be turning the PC into a console any time soon, but it could start to provide a little more predictability.
This is a long-term goal; the Creators Update will contain the first iteration of Game Mode, but it shouldn't be the last. What that first iteration actually does is still something of a mystery. Gammill refused to be drawn into specifics, but he said that it was something along the lines of suspending or deferring unnecessary background tasks and using process priorities and processor affinity to limit any performance impact of multitasking.
What will this all add up to? For games that are currently CPU- or GPU-bound, Gammill said that Microsoft was seeing framerate improvements of 2 to 5 percent.
Game Mode will work for both traditional Win32 games and new Universal Windows Platform (UWP) games sold through the Windows Store. Gammill said that both types of games will see gains but that UWP games may see slightly better numbers. Win32 games can do things like create multiple processes (often used by games with special launchers or copy protection) or install background services, and these are invisible to Game Mode, so they may not be properly optimized. UWP games can't do these things, so they don't suffer the same problem.
The Creators Update will ship with a periodically updated whitelist of known games for automatically enabling Game Mode, in a fashion that's similar to the frequently updated optimization profiles that video drivers include. Windows users will also be able to opt in and out of Game Mode on a game-by-game basis using the Win+G keyboard shortcut. Microsoft plans to offer developers some facility for automatically enabling Game Mode for their software, though it's not clear if this will ship in the Creators Update or at some later point.
At the time of writing, a first Insider Preview build of Windows 10 with Game Mode should become available some time today tomorrow, and Gammill told us that the internal build he was using, which is about a week newer than today's build, shows further improved performance.