Microsoft has advertised the new Xbox One S as an upgrade on the original Xbox One in two key areas: the smaller, more attractive design; and proper support for both HDR content and 4K videos. What Microsoft hasn't advertised is that this new console does pack a small performance boost in some games, as confirmed by Digital Foundry.

The console performance testing experts at Digital Foundry ran a number of games on the new Xbox One S, and came to the following case-by-case conclusions:

  • In Project Cars, performance improves by up to 11 percent (or nine FPS) during heavy rain
  • In Hitman, the Xbox One S was 6.1 percent faster in cutscenes, and 8.1 percent faster in general gameplay, using the game's unlocked frame rate mode
  • In Resident Evil 5 Remastered, performance improvements came in at 2.5 percent
  • In Rise of the Tomb Raider, fewer frame rate drops below a locked 30 FPS were observed
  • In Batman: Arkham Knight, smoothness improved thanks to a 4 percent increase in average FPS, leading to less time spent below the locked 30 FPS target.
  • No performance improvements were noted in Fallout 4.

These minor performance improvements come from a slight clock speed increase to the Xbox One's GPU, along with increased ESRAM bandwidth. On the Xbox One S, the GPU is now clocked at 914 MHz (up from 853 MHz), while ESRAM sits at 219 GB/s (up from 204 GB/s).

The clock speed increases here could be likened to a factory overclocked graphics card, which typically lead to minor frame rate improvements like we're seeing with the Xbox One S. Due to an unchanged CPU clock speed and memory system, games that aren't GPU-limited will see no change to performance, and those which consistently hit their frame rate cap won't improve either.

Microsoft claims the increased GPU clock speed is necessary to facilitate HDR gaming, so the performance boosts in non-HDR games are a byproduct of the hardware changes. The company is quick to note that not every game benefits from increased performance, any any improvements are very minor, which is why they "didn't want to make it a 'selling point' for the new console."