FPS Boost for Skyrim, Fallout 4 and Fallout 76: performance is great - but there is a catch

We've run the ruler over Microsoft's first wave of FPS Boost titles and came away impressed, while our thoughts for the Arkane-developed duo of Prey and Dishonored Definitive Edition were perhaps even more gushing. Our coverage continues with a look at the Bethesda Games Studio titles running on the Creation Engine and impressions are a little more mixed this time. Skyrim lands exactly where we expected and works beautifully overall, but the Fallout titles are a little more puzzling. Despite a wide gap in their respective graphics capabilities, both Xbox Series S and X consoles run these titles at 1080p in order to achieve 60 frames per second, even though Xbox One X targeted native 4K.

The Fallout titles are somewhat contentious then, but it was great to return to Skyrim at least. In this case we have a true 4K60 and it's great to see that the user mod experience we previously tested at Digital Foundry is now made fully official with FPS Boost - though it's worth stressing these use two different techniques to hit this target. The mod essentially works by removing the 30fps frame-rate cap and disabling v-sync for good measure, allowing Skyrim to tap into the extra horsepower of Series S and X consoles (where back-compat forces v-sync back on).

The end result is a very tight lock on 60fps for Series S at 1080p resolution, whether you're using FPS Boost or the mod, while Series X runs at native 4K and looks stunning - the price to pay being a drop to performance whenever volumetrics or full resolution alpha effects are in play. By and large, it's 60fps on both and it adds an extra layer of sheen to what remains an excellent RPG. Yes, the visuals are dated, but the gameplay is golden. And of course, now PlayStation 5 users have access to the same experience via their own mod.

With the Fallout titles, the situation is a little more complicated. Starting with Fallout 4, Microsoft has seemingly opted to push both Series X and S onto the Xbox One S codepath, meaning that the game runs at native 1080p, with the frame-rate cap removed. Bear in mind that the game originally ran at a dynamic 1080p on Xbox One S, rising to 4K on One X. The end result is a pleasing experience that ensures a consistent 60fps for the vast majority of play.

Only the classic bottleneck points such as the Corvega Factory cause issues, with some performance dips on Series X and a more noticeable drop on Series S. By and large though, it's a smooth ride throughout, but you can't help but think that Series X should be doing more. Ultimately, patching in something like an 1800p optional alternative to the 2160p mode seems like a good route forward.

However, there is an alternative if you'd like the best of both worlds on Series X - with 4K and 60fps. Turn off FPS Boost and you're back to 4K30 of course, albeit with far better consistency in play than the game running on Xbox One X. Next step, a '720p60' user mod delivers the required unlocked frame-rate for Series X as well as a push to 4K (search it out in the mods section of the game, activate it and reboot the game). And it's here where you see why Microsoft opted for consistency - frame-rate isn't a locked 60fps while delivering this high resolution. The Corvega throttle point takes you down into the 40s, and there is much more in the way of general instability. It's still a marked improvement over the stock experience on Xbox Series X, mind you, and many may well prefer it. All of which leads us to the multiplayer-focused Fallout 76, where the setup is similar to Fallout 4 while running FPS Boost. This time Series X's 1080p60 output is totally locked, whereas Series S does have some small fluctuations from the target frame-rate. It's not perfect, but it's a vastly improved way to play the game - though again we have lost resolution on Series X using this feature.

Curiously, there is a route forward in using FPS Boost while retaining 4K on the Fallout games running on Xbox Series X - but it's what you might call a loophole, and we do expect Microsoft to patch it out at some point. Essentially, you load one of the Fallout games with FPS Boost disabled, load another title, re-engage FPS Boost on the Fallout game you were playing, then return to the action via Quick Resume. This essentially enables the 60fps unlock benefits of FPS Boost while retaining the One X resolution. It's a trick, it works, but via this you can appreciate why Microsoft made the call to drop to 1080p for their solution. Simply put, 60fps is far from assured playing this way.

In summary, FPS Boost delivers exactly what you'd want from it with Skyrim - turn off the feature and it's a night and day difference, far more so than you'd expect. You just can't go back. With the Fallout games, again, FPS Boost works as you would hope - especially if you're an Xbox Series S owner. You retain the same resolution, and performance mostly locks to 60 frames per second. The Fallout games could be CPU-limited, GPU-limited or even storage limited at any given point - and the improvement delivered by next generation hardware is revelatory. However, Series X forces you to make a choice - 4K or 60fps, FPS Boost on or off. The boost overall is still impressive - the games are so much more fluid in gameplay - but at this point, it's not quite the killer feature we hoped it would be.

Will you support the Digital Foundry team?

Digital Foundry specialises in technical analysis of gaming hardware and software, using state-of-the-art capture systems and bespoke software to show you how well games and hardware run, visualising precisely what they're capable of. In order to show you what 4K gaming actually looks like we needed to build our own platform to supply high quality 4K video for offline viewing. So we did.

Our videos are multi-gigabyte files and we've chosen a high quality provider to ensure fast downloads. However, that bandwidth isn't free and so we charge a small monthly subscription fee of £4.50. We think it's a small price to pay for unlimited access to top-tier quality encodes of our content. Thank you.

Find out more about the benefits of our Patreon

ncG1vNJzZmivp6x7psHRqJ6apZWne6%2Bx02iYq6yZmLmmv46doKChpJa5p7vUp5ursV1nfXN9jJ%2BnrGWSpLy0wIysorKqmaJ6p63LpaaurF1peqety6WmrqxdbIM%3D