The Xbox One S is out, and our review discusses at length some of the system's major changes, including a total visual refresh and a test of its 4K content. Turns out we missed one thing: the system launched with an unadvertised boost to some older games' visuals!

The frame rate-analysis wizards at Eurogamer's Digital Foundry confirmed the good news after testing older Xbox One games. Many titles won't see any boost at all—which is what we found in cursory testing of 15 games, both for the normal system and for its backwards-compatibility library. However, if an older game runs on Xbox One S using either unlocked frame rates (meaning, not tied to v-sync) or dynamic resolution (meaning, it can scale down from 1080p on the fly to improve performance), players might see the a boost by as much as nine frames per second.

That maximum boost was measured in Project CARS, a graphics-intensive driving sim whose rain-soaked racetrack variants can bring frame rates hurtling downward on the normal Xbox One. Other games that enjoyed noticeable boosts included a remaster of Capcom's Resident Evil 5 and the latest game in the Hitman series.

These boosts come thanks entirely to the new GPU's increased clock speed (up from 853 MHz to 914 MHz) and higher ESRAM bandwidth ratings (from 204 GB/sec to 219 GB/sec). Microsoft PR confirmed the boost on older games in a statement while also downplaying expectations of major performance differences: "Our testing internally has shown this to be pretty minor, and is only measurable on certain games, so we didn't want to make it a 'selling point' for the new console," Microsoft's Albert Penello told Digital Foundry. (That may explain why Microsoft never informed the press or fans about this performance update, whether during our hardware review period or even during this year's E3 conference.)

Indeed, it's not a magic-wand solution to other games with frame rate or optimization issues. In particular, Digital Foundry found that Bethesda's Fallout 4 plays nearly identically compared on both the older Xbox One and the newer Xbox One S. Still, these GPU boosts, which were added primarily to aid HDR imaging on future titles, are certainly welcome in this looking-back way. Our own testing found zero crashes or faults with the new GPU on older games, so this change seems to bring only good news.