I have recently bought an ASUS PA328Q 3840x2160 monitor, which I'm using together with a smaller ASUS monitor. I'm using a Windows 10 PC with an nVidia GeForce GTX 780 (3,0GB DDR5 RAM).
When viewing a video on it, the refresh rate seems okay (not sure how I can measure it objectively).
However, when I'm working in a standard application like Microsoft Excel, an editor like Notepad++, or in Visual Studio, I notice something that feels like a refresh rate lag. The mouse cursor always seems to be a bit behind. It feels like working on a remote workstation through some kind of VPN solution (like Remote Desktop or TeamViewer), where it takes a fraction of a second for the mouse cursor to move. You move the mouse, and the mouse cursor follows a little bit later.
Here's something to demonstrate the problem. If I move the mouse in a fast circle, then on my old monitor it looks like this:
However, on the 4K monitor, it more looks like this:
This is the reason I'm suspecting a refresh rate problem. The rate at which the mouse cursor position is updated is way lower than on the old monitor.
Now, I have absolutely no idea where to go look for the problem. Could it be a problem with the graphics card? With the monitor? With the configuration?
How can I tell where's the problem?