After initially rolling out the upgrade to a handful of popular titles, Microsoft has now released a new crop of boosted games, including Assasin’s Creed Unity, Mad Max and Wasteland 3, bringing the total number available to 97. You can find the full list of compatible games in Major Nelson's latest blog post.
FPS Boost allows the frame rate of certain classic games to be upped to 60fps, 90fps or 120fps, which in some cases is quadruple the frame rate of the original and should mean smoother motion, less blur, and more immersive gameplay.
Microsoft has said that to enable FPS Boost for certain titles with more demanding graphics, such as STAR WARS Battlefront II and Battlefield V, the resolution has to be dropped to ensure smooth running. In those instances, FPS Boost is not automatically activated but can be turned on in the 'Compatibility Options' form the 'Manage game and add-ons' setting.
You can also check if you're running FPS Boost while playing by tapping the Xbox button on your controller, and a guide indicator in the upper right corner will display if the feature is engaged.
To take advantage of FPS Boost, you need an Xbox Series X or Series S (though not all titles are available on both consoles) running the very latest firmware.
Read our Xbox Series X review
Compare the features: Xbox Series X vs Series S