I'm dual booting Pop_OS and Windows 11 for now while l try things out. I went with Pop_OS for the NVIDIA drivers, since I have a NVIDIA card. Installation went smoothly, but setup is where things started to get a little weird.
I have 2 monitors, a main 360hz monitor and a secondary 165hz monitor. I seem to be able to have them both working at the same time in Windows 11 without issue, but in Pop_OS, setting the refresh rate to 360hz on the first monitor causes both displays to stop working properly. The 360hz monitor will stop displaying picture all-together, and the 165hz monitor will start flickering wildly. Turning off the second monitor brings the 360hz's image back, but then I'm down a monitor. Also, if I set the refresh rate to anything lower than 360hz, they'll both work. I'd like to still be able to use it at the native refresh rate, but I can't seem to find any other solutions or anyone else who seems to have had this same issue.
My second (slightly less annoying) issue is that I can't seem to use HDR in games. Is this normal, or is there something I can do to bring back support?
Also, if Pop_OS isn't the way to go, please let me know! I tried Nobara first, but immediately had issues with the displays locking up and flickering before I even got it installed.
PopOS is currently using modified GNOME on Xorg. It’s impossible to get mixed refresh rates on Xorg/X11 (which is the legacy display protocol) and with your setup you are pretty much stuck with Wayland (the modern display protocol still, still progressing as a platform) - which is what you tried first if you used Nobara, whether it’s KDE or GNOME.
Note that PopOS 24.04 (that will be released this fall iirc) will in fact run on Wayland with all new Cosmic desktop (it’s first full DE written from scratch since like 90s) and promises great NVIDIA support - which can definitely be the case given recent updates.
Now on the flickering issues that you experienced, they’re specific to the NVIDIA driver and are just being ironed out. There is the new explicit sync Wayland protocol, new NVIDIA driver, patches for XWayland, patches for Mesa, maybe something more. It still might require pulling something that didn’t make it to stable distro repositories, but I think Nobara provides that and for sure will when 40 will get released soon-ish. I don’t have NVIDIA GPU, but I saw conversations on Nobara Discord and they help each other get NVIDIA going so maybe ask there.
The time frame is a bit of a problem here. If you want to avoid tinkering, hold for a little longer and in few months most distros (that ship a Wayland session) will most likely just work with your setup. If you want it now, feel free to get your hands dirty and find a way to run NVIDIA on Wayland with explicit sync support.