Data analysts Ampere says that Xbox Series S is out-selling Series X across several key markets.
GamesIndustry.biz has also seen figures that show S and X are at least 50/50 in terms of install base in major territories.
As a result of the success of Series S, which is a digital-only device, Xbox game sales are heavily digital, even compared with PS5. According to GSD data, over 90% of sales of Call of Duty: Vanguard on Xbox came as a digital download.
Ampere's latest hardware update pins Xbox Series sales at 6.7 million units as of the end of September 2021. This is versus 12.8 million for PlayStation 5.
The data firm's Piers Harding-Rolls notes that PS5 supply improved significantly during the July to September window, which saw the PlayStation console outsell Nintendo Switch across Europe during that time. PS5 also managed to outsell Nintendo's console in September in the US, according to NPD.
However, he notes that Switch is likely to reclaim its place over Christmas thanks to the launch of the new OLED edition, improved supply and the fact Nintendo tends to perform very well over the Christmas period.
Finally, Ampere analysis says that PS4 sales have dropped off faster than they previously estimated, and says it is unlikely the console will enjoy the same long-term success as the PlayStation 2.