As someone who owns a 240hz monitor, absolutely. And here's how I can probably immediately convince you that I can as well: drag your cursor at a rapid speed a

As someone who owns a 240hz monitor, absolutely. And here's how I can probably immediately convince you that I can as well: drag your cursor at a rapid speed across your screen back and forth (e.g. 2-3 times across the width per second). Focusing on one spot, do you see individual cursors with gaps of background in between? (I'm assuming yes.) Now on 120 Hz the gaps will be half as big as on 60 Hz. On 240 Hz they are half as big once again, but they are nevertheless noticeable. The size of the gaps easily allows you to distinguish between 120 and 240 Hz. Until I can drag my cursor across the screen and see nothing but a continuous moving object, we haven't hit diminishing returns on monitor refresh rate yet.