I play video games at a decently high level (like top ~10% in a few competitive games). To support what you’re saying, I can tell the difference between 144hz and 240hz if I’m in control. For example, if I can shake the screen around.
If I’m just watching, I’m not sure I could even tell the difference between 60hz and 144hz.
esports games are played with vsync disabled, which means you'll get tearing when there's a rendered frame update in the middle of a scan. At 60Hz, you'd definitely see the tear, at 144Hz much less. So that would be a way to notice the difference as a third party observer.
tverbeure|7 months ago