I have not done extensive testing and the testing I have done is only on the Steam Deck.
I found that when comparing a normal Windows 10 installation to SteamOS, SteamOS performed better (slightly more consistent FPS and better battery).
When I switched to the LTS version of Windows 10 (which doesn't have a lot of the bloat in it and you don't run the risk of screwing things up by running a debloat tool) I got slightly better performance on Windows than I did on SteamOS.
This is also not on a higher end PC. I choose to keep my gaming PC windows right now just to not deal with lower performance, I paid a lot for this computer since I value performance on it.
I will say however that I am finding myself using Windows on my Steam Deck more often. Like right now I am replaying through the Kingdom Hearts series. It feels like jumping through hoops to get that to work on SteamOS where on Windows I just installed the Heroic Game Launcher (alternate app for epic games), installed it and it just works.
I found that when comparing a normal Windows 10 installation to SteamOS, SteamOS performed better (slightly more consistent FPS and better battery).
When I switched to the LTS version of Windows 10 (which doesn't have a lot of the bloat in it and you don't run the risk of screwing things up by running a debloat tool) I got slightly better performance on Windows than I did on SteamOS.
This is also not on a higher end PC. I choose to keep my gaming PC windows right now just to not deal with lower performance, I paid a lot for this computer since I value performance on it.
I will say however that I am finding myself using Windows on my Steam Deck more often. Like right now I am replaying through the Kingdom Hearts series. It feels like jumping through hoops to get that to work on SteamOS where on Windows I just installed the Heroic Game Launcher (alternate app for epic games), installed it and it just works.