On the NeoGAF forums, a verified industry professional going by the name of BGs revealed that, as of January, the PlayStation 5 is still offering better performance than the Xbox Series X. This may have changed with the latest Devkits, but he has no way of knowing right now as he will get access to them later this year.
At the beginning of the year PlayStation 5 was still the one that offered the best performance. I don't know if that has changed with the new Devkits, I don't have access to that information at this time and personally I think that (theoretically) I won't have physical access until early summer, for my part.
This generation will NOT be the generation of the visual difference that makes you decide what to buy. It will be the generation of the games. Yes, one will be faster than another (but you will not notice it in practice). One will load the screen in 10 seconds and the other in 7 seconds. One will have a better sound than the other. One will run the game at 60fps and the other ... too. What will really matter will be the quality that development studies can achieve with their time and budget.
https://wccftech.com/playstation-5-best-performance-xbox-series-x/
Czyli informacje od redaktora Kotaku się sprawdzają. Dodatkowo kilka źródeł podaję, że największą różnica będzie dysk SSD, ten w PS5 ma być szybszy.