Just thought it was nice to see some performance benchmarks that made appropriate use of upscaling.
Upscaling to 4k is definitely doable, but the more demanding games are more likely to be better suited for 30-40 FPS caps than 60.
I was curious what the feasibility was of Steam Machine using FSR 4.1 to target “4k 60 FPS”, so I did some math to show what fps would be needed at the native internal resolution to be able to achieve both 60 and 30 fps with FSR 4.1 in the future. The leaked FSR4 int8 model currently has a fixed cost of ~10ms per frame at 4k with an RX 7600 (as seen in Optiscaler results), so the Machine’s slightly weaker GPU is being estimated to roughly cost ~12ms per frame. The official AMD release should improve performance by an unknown amount, so there is a range of performance targets based on how much FSR 4.1 might cost, with the existing ~12ms cost being the worst estimate and 6ms being the best if the new method performs a lot better on RDNA3.
As an example, if you want a game to run at 4k 60 fps (16.66ms per frame, a 12ms upscaling time means that the game itself has to be running at 215 fps (4.66ms) at the resolution you are scaling from to run with that upscaling at 60 fps. Some other numbers if the upscaler time gets lowered with the new model:
Upscaler time: 60 FPS 30 FPS
12ms................. 215.........47
11ms..................176.........45
10ms..................150..........43
9ms...................131.......... 41
8ms.......,............115..........39
7ms..............,.....104..........38
6ms..........,...........94..........37
Even with a modest increase to performance with FSR 4.1, in the 8-9ms upscaler cost range on Machine, it would require ~120 FPS at 720p native to use 4k FSR 4.1 Ultra performance mode at 60 FPS. Not impossible in some games, but it's quite a lot to ask. 40 or 50 FPS could end up being good alternatives because the extra frame time means more for rendering the game instead of upscaling, which can be seen in the results for targeting 30 FPS having a lower percentage of performance impact.
As others have suggested before, it might be better to target 1440p with FSR 4.1 and use SteamOS FSR1 to take care of the rest to save some performance (and maybe VRAM). You're still likely to get a better-looking result than using FSR 3.
Let me know if I have messed up the calculations or anything. And yes, I have too much free time.
TL;DR - FSR 4.1 probably won't "save the day" in that respect, but it will still at least be usable at lower resolutions to good effect, or even for a 4k 30 FPS that looks quite good. FSR 2 / 3 will still be options that trade image quality for better performance.