You will have to use wayland to run monitors at different refresh rates without tearing. You will also need wayland for HDR. It’s still not working perfectly yet, but there is a lot of work being put into it.

Popping in to give an update before calling it a night!

First of all, thank you for all the help! I’ve been reading through all the comments here and trying a few things out. The first thing I tried was switching the default desktop environment from the default Gnome to KDE. I much prefer KDE to Gnome since I have experience with it on the Steam Deck, so this is the solution that I had the most hope for. Sadly though, things are much worse in KDE. Unlike in Gnome, KDE has the terrible screen tearing that was mentioned in X11, but is still similarly unable to support running the monitors at different refresh rates. Since a lot of the comments here mentioned Wayland though, that was my real end goal in getting KDE installed. Unfortunately, witching over to KDE Wayland, things became significantly more unusable and it was about the same experience I had while trying to install Nobara. Both displays were totally unresponsive for seconds at a time and I was only able to interact with things during brief moments when they would stutter along instead. This was pretty painful to log back out of and was an overall mess like a couple of you had mentioned it might be.

I went back to Gnome after this. Since KDE didn’t seem to be they way forward, I figured I might as well try enabling Wayland on Pop_OS’s built in solution. Wayland support was hidden by default on NVIDIA as mentioned, but one quick config edit later and the option appeared. Things seem to be going much better now! I’m running Gnome Wayland right now and while things aren’t flawless yet they’re significantly better than before. Both monitors are working at their full refresh rates now without any screen tearing or flickering. As for gaming, so far I only have Helldivers 2 installed running through Proton, and performance is about 8% worse than in Windows on the same graphics settings while on the ship. I am also getting an odd visual bug where the in-game menu looks like it opens and closes very quickly every once in a while. It’s not actually open or intractable though, it’s more like the game randomly displays a single frame from when I did have the menu open to change the graphics settings. Tomorrow I’ll try enabling Proton experimental and see if that fixes anything, and also try installing some more games.

I’ll come back again to give an update on how things are going then! I’m still lacking HDR and there are other bugs that look like they need to be ironed out, but I’m much more optimistic about this than I was before. I think I’ll keep dual-booting for now, at least while I’m still trying to get everything working properly, and hopefully that next version of Pop_OS brings HDR support. For now, it’s at least nice to know that different monitor refresh rates are working.

I recently bought an AMD card just to not have to deal with Linux NVIDIA nonsense anymore. I know not everyone can be in a situation that allows them to do this. But if you can, and if you don’t want to wait on the hope that all the NVIDIA issues will be resolved when explicit sync finally hits all the distro repos and the NVIDIA driver (it’s going to still take some months), I’d advise going AMD.

I’ve had nothing but buttery smoothness since switching, running Wayland with two displays at different refresh rates, and gaming works phenomenally well with no frame loss that I can tell and no stuttering/tearing.

If you are more patient than I and continue with NVIDIA, I wish you all the luck and hope the trickling in of the various fixes and libraries and drivers happen rapidly.

You are likely using X11. X11 treats all enabled displays as one “screen” and therefore different refresh rates will have issues (as will VRR for example).

Wayland is the way to go, but the NVIDIA drivers are still buggy with Wayland. Pop!_OS currently uses a desktop environment based on an outdated version of GNOME, so it probably won’t be amazing under Wayland.

I’d recommend using a distro with a recent version of KDE Plasma as it has non-experimental support for VRR and great support for Wayland. You’ll also want an up-to-date kernel and the latest NVIDIA drivers. I recommend Fedora KDE Spin or openSUSE Tumbleweed. Installing NVIDIA drivers is a little bit more involved (search for “RPM Fusion NVIDIA” for Fedora), but very doable.

I personally switched to an AMD GPU because of the issues with NVIDIA, but NVIDIA support is improving so you’ll probably be fine.

Please do an update later on. I also want to try out Linux gaming. Gaming is the reason I keep going back to Windows.

many linux distributions still use the older method of getting things to appear on screen.
they rely on a program called x11, development on x11 has stopped in favour of a new system called wayland. x11 does not support running different displays at different refresh rates, wayland does.
but nvidia doesn’t support wayland very well yet. you can use it, but it might be more prone to crashes when using an nvidia gpu. i still recommend trying it.

usually you will find a menu at one of the corners of the screen before logging in to your desktop. here you will usually find something like “desktop name (xorg)” and “desktop name (wayland)”.
but some software hides the wayland option from nvidia users, it shouldn’t be too difficult to find a guide on how to make this option appear if it is hidden though.

HDR support is still a work in progress. Afaik it’s not part of any official standard for display technology on linux yet, but KDE Plasma 6 has experimental support and Valve is actively working on support.
KDE Plasma 6 is currently only available on distributions that push updates more frequently, without testing said updates thoroughly, like arch linux and some derivatives. the pop os developers have also promised to support HDR in their upcoming desktop environment called cosmic, which might still take a while to be released

So yesterday, I tried Bazzite os, and it’s pretty good. Works perfectly with Nvidia GPU. You have to use x11 instead of Wayland. So far, I’ve tested BF1 and Hell Diver 2. Experience is excellent, with no lag whatsoever. It’s the first time I’m giving Linux a proper shot. However, I will need some advice on optimising it. For example, fan control or any other tips/tricks I can get.

(I had app flickering issues, and changing to x11 fixed it)

Dual monitors are working perfectly with 165Ghz refresh rate.