Using intel integrated graphics, mesa drivers; on Linux (any distro) I don't seem to have a 1280x720 resolution (which is the only one I use to play games on Windows). I wanted to do the same but on Linux I only have these Doesn't the driver support it? Is there any way I can add that resolution?

I know this is unrelated to Solus

Have a look at xrandr it's in the repo. Just use your favorite web browser to find documentation or a tutorial .

tothecloudd0

tothecloudd0 but I had to enter in my 3840x2160 resolution manually

Thats probably what I need to do then. I was surprised to see its not there; I mean, it's not like it is an uncommon resolution, quite the opposite even.

      Actually, now that you mentioned that... I do have an option to set to 1280x720 after I checked. I only had to add the 4k resolution manually but everything else was in place up to 1920x1080. But try the xrandr out, all systems are different ¯_(ツ)_/¯

        tothecloudd0 Hey, just a quick question, do you have the 60Hz refresh rate avalaible by default with your 4k resolution?
        Mine is locked to 30Hz and I can't set it to 60 using xrandr via custom mode... So I have to scale down...
        Does anyone have the same problem?

            Monsieur_Caillou This is going to depend on several factors:

            1. Monitor support - some early 4K panels were only 4K30
            2. Graphics card support - Needs to be HDMI 2.0 or newer or DisplayPort 1.3 or newer
            3. Cable type - This one is something that a lot of people get wrong. Most monitors can only do full resolution over certain interfaces. VGA rarely supports anything as high as 1080p. DVI has several different types and only dual-link can do high resolution. HDMI is limited by the version of the specification supported by the GPU output and in rare cases the quality of the cable. DisplayPort was the first interface to support full 4K60 and many cards with both DisplayPort and HDMI of that error will not be able to do more than 4K30 over HDMI. Full 4K60 requires at lease HDMI 2.0 capability.
            4. Internal displays on laptops - Sometimes the GPU is not powerful enough to handle both the Primary "internal" display and an external display at their maximum mode settings. You may need to reduce the resolution of one to boost the resolution of the other. You may also need to disable the internal display entirely.
            5. Derpy EDID - This is most likely what @Zenurik and @tothecloudd0 have encountered. EDID is a negotiation between the Montor and the GPU for what modes to run at. In some rare occasions Linux has difficulty reading all of the modes via EDID.
            6. Multiple Monitors - Your GPU may only support 4K60 for a single monitor and have to reduce the resolution of this monitor to allow for other connected displays.

              Monsieur_Caillou as a matter of fact, I do have an option to go to 60hz since I set it via xrandr but whenever I do, there's screen tearing by where Raven/notification is so I just stick with 30hz. Like @DataDrake said it sometimes depends on cable type and version. I did a little bit of research and I think my current limitation is just my old gpu (HD 6870) since I'm already running 2 monitors (1080 and 4k)