Swaync laggy on 4k monitor?

[LucaAAntonelli]

Hi guys, I'm using Sway as a notification center on NixOS together with wayland and waybar. My problem: the notification center seems to work well on my laptop as well as on my 1920x1080 monitor, but the mouse cursor stutters when I move it across swaync (only on the 4K monitor). When inspecting GPU usage, I get huge spikes in vram load when I move the mouse, otherwise the usage is pretty low. Is this a hardware issue, i.e. a GPU that would need to be upgraded?
Thanks in advance!

Update: Probably worth mentioning my GPU. It's a 1080TI by Nvidia from 2018