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I have a Dell monitor with 60 Hz refresh rate and therefore games playing on it are not very smooth as compared to 120 hz. But when I open videos on YouTube of the same game on the same monitor, some of those videos run extremely smoothly as if it's a 120hz display.

Why is that so ?

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As you have now mentionned that your computer can actually keep up (at 150 fps no less), I suspect you have a case of temporal aliasing.

The problem is that 150 is not a multiple of 60. Let's say we look at one tenth of a second. That's 15 frames generated by your computer but only 6 can be shown on your screen. The frames you will see will probably be something like:

#1 - #3 - #6 - #8 - #11 - #13

Notice how the increment is +2, +3, +2, +3. This will cause animation to not look smooth. There is no steady increment which will let you display 60 frames out of 150.

As I wrote in the comments below, forcing the game to run at "only" 120Hz should help as the screen should show every other frame.

Enabling vsync is even more reliable but it seems your game does not deal well with latency then.

By the way, that's why serious gaming monitors now have adaptive refresh rates. They just show the frames when they're ready and have none of the above issues.

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  • $\begingroup$ I'm talking about CSGO here. In game, I get 150 FPS but it doesn't look smooth. But some csgo videos on YouTube look real smooth. $\endgroup$ – Aryan Sethi Jan 15 at 20:42
  • $\begingroup$ @AryanSethi too much fps might be part of your problem too, causing temporal aliasing. Try enabling vsync so you only get 60 fps. If this helps, let me know as the explanation is entirely different and quite interesting. $\endgroup$ – Olivier Jan 15 at 20:49
  • $\begingroup$ Okay I already tried 2 things. First is that I tried enabling v sync, it did make my game smooth but the the mouse latency obviously increased like crazy. The second thing I tried was limiting my fps output to a 60,100,150 and no limit, the game worked smoothest with no limit(still not even close to those smooth YouTube videos ) $\endgroup$ – Aryan Sethi Jan 15 at 20:52
  • $\begingroup$ @AryanSethi so yeah, likely temporal aliasing. I will edit my answer then. Input latency is a whole other problem which is in part caused by game design. If can run at 120fps (2x your refresh), you might get good results. $\endgroup$ – Olivier Jan 15 at 20:58
  • $\begingroup$ So why is this happening exactly what's the solution $\endgroup$ – Aryan Sethi Jan 15 at 21:02
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Humans dont really see anything beyond 20-25 fps. Even less is often sufficient animation at 12 frames a second work quite well too. So when you watch tv the fps of your image is 25-30, and yet you dont generally accuse of them being nonsmooth.

Why do games require more? Well, because they are fast paced. There is generally a slight benefit from going to 30 to 60. But mainly it comes down to:

  • Games do not generally have temporal antialiasig, aka motion blur its expensive.
  • The game simulation is locked to the rendering loop so that your input reactions now have a higher rate of feedback (wetware is not digital, reflexes do react faster)
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  • $\begingroup$ Please stop propagating the myth that we can't see beyond 25 fps. Most people can easily see the difference between 60 fps and 120 fps. $\endgroup$ – Olivier Jan 15 at 20:43
  • $\begingroup$ @Oliver it depends on what you define as see the human system is obviously analog. So defining a FPS to senses makes little sense. But yes it may be better to say that beyond some frequency humans interpret the data as continious. But offcourse if your data does not align with how the senses work no matter how many FPS you have humans see it as nonsmooth. In games yes you can see higher FPS because the processing window is smaller but only if your practiced in that type of focus. Same aplies to people who do rally, formula1, fighter pilots, ski jumper etc. $\endgroup$ – joojaa Jan 15 at 20:49
  • $\begingroup$ Perhaps but 24 fps is not that threshold. Not by a long shot. IMAX theaters made that obvious decades ago. And this was "rediscovered" with large HDTVs more recently. $\endgroup$ – Olivier Jan 15 at 20:54
  • $\begingroup$ @Oliver the measurements in experiments move slowly. The slower the movement the easier it is for the human brain to decide that its the same source. If you move fast its harder. The faster you are the more hints brain needs. This is why hand animators can get away with hideusly slow framerates they can build a smeared or deformed hint for fast movement. So gemporal aliasing clearly helps. On the otherhand a lot of jitter in the path may cause brains to decide that they are not seeing one continious motion. Again fps help to make need for temporal aliasing lower, since games tend not use it. $\endgroup$ – joojaa Jan 15 at 21:31
  • $\begingroup$ Its hard to say that we see it, we just compile it to a motion. Anyway there is a correlation with speed of movement speed and understanding that movement is continious. $\endgroup$ – joojaa Jan 15 at 21:32

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