Make sure the "Game Resolution" dropdown contains the quarter resolution of the display, plus other divisions/multiples

[cheater]

Sometimes, highly demanding titles require scaling back the Game Resolution dropdown. This is apparent when using external 1080p, 2.5K or even 4K displays. It's also apparent when using the DeckHD, which is an aftermarket internal screen that is 1200p.

Having been using the DeckHD for several months now, I can say that the best way to do things for AAA titles that will not run well at 1200p is to run them at 600p (960x600) and then scale the graphics up in SteamOS's own FSR1 scaling method in the QAM. This is by far the cleanest and best looking way to get sharp images while also having high framerate performance. FSR1 really looks good when doing integer scaling.

However, currently SteamOS does not allow 960x600 to be set in the Game Resolution dropdown in the cog settings. This means that this resolution is only available if the game itself lists it. Some AAA games do not list it, for example Baldur's Gate 3 which is my favourite game. The only closest resolution is 800x600 which while it performs well obviously has black bars which are unwanted.

For this reason, when a screen is connected which is x pixels wide and y pixels tall, please also list resolutions that are x/2 wide by y/2 tall. In this case, since the DeckHD is 1920x1200, the idea would be to add the resolution 960x600.

It is crucual for me to be able to select 960x600 in the Game Resolution dropdown.

The following is optional and might be a good bonus when doing the work necessary for the above:

In addition to the above (quarter resolutions), you might want to add /9 ("ninth") resolutions as well, where both vertical and horizontal resolutions are divided by 3. This would especially be useful with external 4k displays etc. As numbers often don't divide by three, use integer division. So, for example:

1280x800 -> 426x266. Note that in this case, scaling that up by three times gives us 1278x798, but no one's going to be upset at one or two pixel columns missing.

1920x1200 -> 640x400. Note that in this case it's a perfect integer division.

2560x1440 -> 853x480. Note that scaling this up by 3 gives 2559x1440, but again, no one's going to be upset about one pixel row missing. This would be a great setting for someone playing a very demanding title on a 2.5K screen.

The most obvious example as to why a /9 resolution is useful is 4K:

3840x2560 -> 1280x720 (perfect integer division). Since this is a typical resolution the Deck is made to handle, it makes sense to have a /9 resolution. While 1280x720 already exists in the Game Resolution drop down, it would be good to have this sort of logic available to all sorts of displays. For example, oled displays now often come in weird resolutions, such as 2480x1860.

This would help people optimize their performance while using integer resizing and FSR upscaling, which gives perfectly sharp results.

P.S.

Some people would call those "half" and "third" resolutions, either nomenclature is fine. I added this so that people can find this issue.

Edit: updated wording to default to "quarter resolution" which is more widely accepted.

Edit 2: added more info about /9 resolutions.

[cheater]

While this has been marked a duplicate of #1792, I think this must have been a misunderstanding. I explain that here in a comment to #1792.

[cheater]

It would also be useful to be able to set 2x and 3x resolutions. While modern AAA titles will obviously not run at such high resolutions, old titles and modern indie titles definitely will do that without a sweat. For example, Balatro could use some antialiasing, and so could Antichamber, both titles that don't have AA settings in-game. Countless older titles would benefit from this as well. They'll run at extra high resoltions without any issue at all.