I tend to play stuff at 40fps because my experience of it is that I feel like I’m getting 90% of the way to 60 (playing a lot of 30 until mid-20s will do that to you!), and then shift up to 60 if I have headroom or the game in particular feels rough at 40. My main machine has a 120Hz monitor and it’s lovely for some games, but it’s something I ‘feel’ on the mouse more than I ‘see’. I just can’t imagine using it on my deck for the vanishingly few games that can hit 90 on the Deck and then caring.
But, I’ve seen claims like ‘setting it to 40Hz will make it run 40 in an 80Hz container’ (some Nerd Nest video or the guy on it who does a lot of battery testing), or the PCGamer review which states the OLED can take “a game locked at 30 fps and triple each frame so it runs like butter at 90Hz”.
Is this just referring to, say, response time / latency?
Thats plain wrong, why do you think vrr is a thing. If you have 30 fps while running a 30hz screen and then dip to 29 fps, you will miss a frame and wait for next refresh, so instead of 33.4ms between each frame, you get one frame that will be delayed by 66.8ms.
If youre running 90hz and have 30 fps dip to 29, that one frame will only be delayed by 44.5ms instead. Since a refresh happens every 11.1ms instead of 33.4.
If you have 100% locked 30fps in games it doesnt matter, but almost no game will always run 100% locked with 0 fluctuation.
To add to your statement, which is correct, SD’s LCD screen flickers at anything other than 60hz, so some people might experience dizzines, eye strain, headaches, and so on, when playing at say 40hz, with the OLED they might play 40 fps at 80hz and avoid said issues.
No you are wrong. The VRR is different because it does it on the fly so you do not need to lock the Hz. Steam Deck does not have VRR, so it has to lock, but can lock to any Hz you want. Is not limited to 90Hz.
Lets say you have a game that fluctuates from 30fps to 50fps. On the Deck your best option to to lock at 30Hz (or an integer multiple). This looses the extra fps but this is not that bad, you get it on battery life. On ROG Ally that has VRR you can live it uncapped and get all the extra fps which is nice (and also have less than an hour battery life)