Xbox Series S backward compatibility could double Xbox One frame rates with as few as “three lines of code”

Backward compatibility has been thrown into the spotlight again after the announcement of the Xbox Series S, with the lower powered console able to play all the same games as Xbox Series X can, but questions raised over if and how it can enhance those games compared to the Xbox One S and Xbox One X.

Microsoft have now detailed (via Digital Foundry) just what the Series S will be capable of across the whole range of backward compatible titles.


For original Xbox and Xbox 360, the Series S will be able to meaningfully upscale and enhance those games. In a similar fashion to the Xbox One X and Xbox Series X, the emulation layer will be able to up the game’s rendering resolution on select games – the same ones already listed as Xbox One X Enhanced.

This will be done in line with the Xbox Series S’ 1440p target resolution from Microsoft, so enhanced Xbox games running at 480p will be given a 3x boost on both axes (giving us 9x the resolution), while Xbox 360 games will have their 720p resolution doubled. In both cases this results in a native 1440p. These can then be further upscaled by the Series S to 4K resolution.

Much more interesting is the situation with Xbox One backward compatibility. As was previously confirmed, the Xbox Series S will not be able to take advantage of Xbox One X Enhanced modes in games. Though the biggest benefits here came from resolutions up to 4K and performance modes for higher frame rates, games could also have higher detail game assets that make use of the Xbox One X’s larger amount of RAM. In other words, Series S backward compatibility will play games in One S mode, restricted to any resolutions and frame rate limits that developers coded for – often this could top out at 900p instead of 1080p – but able to use the power to stabilise dynamic resolutions and frame rates at their highest setting.

However, there’s still the possibility to meaningfully enhance games beyond that. On a system level, the SSD will reduce loading times and Auto HDR can will add HDR to games that don’t natively support it, but Microsoft have talked up the ease with which developers can add Series S specific resolution and frame rate modes.

System architect Andrew Goossen told Digital Foundry, “We made it easy for existing Xbox One S games to be updated to run with double the frame-rate when played on Series S as well. When games are updated, existing games can query to determine whether they’re running on the new console. And in terms of the performance, the Series S provides well over double the effective CPU and GPU performance over the Xbox One, making it pretty straightforward for the games to do this. And in fact, the Series S GPU runs the Xbox One S games with better performance than the Xbox One X.”

Because of that, “There’s no real perf tuning necessary when you do this, and so often it’s just as easy as changing three lines of code, and then the game works.” Sometimes it’s not quite that simple and some elements in games can be tied to certain frame rates, but Goossen emphasises that these should be simple to fix as well.

As for which games will be enhanced? Well, games with large communities and active development will likely be enhanced like this, sp even if the developers don’t plan to make a dedicated version for Xbox Series X|S they could be improved, but Microsoft are working with as many developers as possible to try and have games enhanced.

Microsoft’s compatibility team could also take over, as they have for the process of enhancing Xbox and Xbox 360 games. As in those cases, there’s ways to override a game’s coding to enable different texture filtering, modify resolutions and so on, but it seems that Microsoft will continue to do this in collaboration with developers instead of making unilateral changes.

It’s quite a fascinating proposition, but will really depend on how widely it’s adopted by developers. I’m sure that more recent games still being patched will likely roll such changes into their next update, and some legacy games that had Xbox marketing partnerships like the Assassin’s Creed or Tomb Raider series could be nudged to have such changes made, but don’t expect something like F1 2017 or Black Ops III to get tweaked.

Source: Digital Foundry

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  1. Just because developers can, doesn’t mean they will. And I wonder how far Microsoft’s compatibility team will get before publishers realise that this may prevent them from reselling remasters.
    Still, if it works it will be awesome for players.

    • It’ll likely be focussed on more recent and more active games. They got pretty far with BC and One X Enhanced games, which was all done in collaboration with pubs/devs and boosted catalogue sales.

    • They don’t have to – MS do the work themselves a lot of the time

  2. 10 PRINT “Loading Enhanced Framerate…” #They’ll never notice the difference :D
    20 PRINT “Loading Complete!” #rofl
    30 GOTO 10

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