Microsoft has worked extensively with Digital Foundry to prove the power of its recent consoles, exuding confidence in the power and architecture of their systems. Microsoft has also not shied away from describing the Xbox Series X as the "world's most powerful console," and the spec sheet certainly seems to indicate that to be the case. Like with most gaming and computing hardware, though, there's far more going on under the hood before we get real-world performance, and thus far, the PlayStation 5 has generally proven itself to run multiplatform games better than their Xbox Series X counterparts, so what gives?
Digital Foundry has tested a range of titles, from DiRT 5 to Call of Duty, and games with special marketing deals with the Xbox platform like Assassin's Creed: Valhalla. For the vast majority of these tests, the PlayStation 5 seems to provide a better experience, with the 2TF performance gap enjoyed by the Xbox Series X nowhere to be seen.
In a statement to The Verge, Microsoft fell short of claiming it would be able to beat out the PlayStation 5 in the future but seemed to indicate that there are "minor bugs" that could be impacting performance. Microsoft also inferred that developers still need to learn how to "take full advantage" of their new platform.
"We are aware of performance issues in a handful of optimized titles on Xbox Series X|S and are actively working with our partners to identify and resolve the issues to ensure an optimal experience. [...] As we begin a new console generation, our partners are just now scratching the surface of what next-gen consoles can do and minor bug fixes are expected as they learn how to take full advantage of our new platform. We are eager to continue working with developers to further explore the capability of Xbox Series X|S in the future."
Through our own sourcing, we've heard from developers at two separate publishers that Microsoft is working to issue a GDK (game development kit) platform update before the end of the year to address specific bugs that cause performance degradation in certain situations. Whether this is the same bug across the board that seems to be draining performance in games like Observer and DiRT 5 remains to be seen, but it's certainly not without precedent for a new video game console to launch with these kinds of issues.
Update November 27, 2020: Assassin's Creed Valhalla has been updated recently, with fixes to screen-tearing. It also seems to now run at a locked 60 frames per second on the Xbox Series X, potentially leveraging the platform fix outlined above.
The Verge also reported that next-gen Xbox consoles only entered manufacturing in the summer, with Xbox lead Phil Spencer revealing that Microsoft waited for specific AMD tech before beginning mass production. It certainly seems as though some developers may have had far more time with PlayStation 5 dev kits to build out and optimize their titles, with leaks of PS5 dev kits appearing around this time last year.
Regardless of optimizations, this whole saga is a reminder that on-paper specs don't necessarily translate to real-world performance. Mathematically speaking, the Xbox Series X should be the more performant device, but there's no way to know how long it could take before the spec sheet translates into real-world results.