I came across something interesting last night when I was using my Deck docked to my TV. I’m going to try to make the description as understandable as possible.
With the recent stable 3.5 update, system-wide FSR seems to be broken for everyone when the Deck is docked, at least when a 4K TV is involved; when enabled, every game I tried was locked to about 15fps. I had read that a fix for this is to manually set the system resolution to 1080p in the system settings, and lo and behold, that did in fact fix the framerate with system-wide FSR enabled. The thing that surprised me, though, was that the graphics of the game that I was trying this with – Yakuza Kiwami – looked better on my 4K TV with system-wide FSR on when the Deck was set to 1080p than when it was set to 4K. Like, noticeably better. Everything was so much more crisp and clear with the system resolution at 1080p than at 4K.
Yakuza itself was set to 1280x720 in the in-game settings throughout all of this. I tried the same thing with Resident Evil 7 later on, and it was the same result: With system-wide FSR enabled, it looked undeniably better when the Deck was set to 1080p instead of 4K, even if I set the in-game resolution to 720p, like I had done with Yakuza. Am I just not understanding how FSR works, or is my TV doing something weird that I’m not realizing? 1080p looked almost like native 4K in my tests, and everything using the same settings but with the display set to 4K looked noticeably blurrier. I have no complaints at all with my findings, I’m just wanting to learn more about why it is the way it is.