FPS capping question

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Dew
Posts: 10
Joined: 07 Sep 2014, 11:19

FPS capping question

Post by Dew » 07 Sep 2014, 11:25

Hello everyone. I have read a few very helpful posts here about capping your FPS. I have always used msi afterburner to cap my FPS at 120 on my 120Hz monitor which results in small and sharp tear that constantly rolls downward through the screen. This isn't that bad to me.

I recently read Chief's article about these programs that cap the FPS causing extra input lag so I tried doing the same thing in the game engine. Unfortunately when I use fps_max 119, 120, 121 etc (source engine game) I get a large bar of tearing that is extremely distracting.

Also the frametimes are different using both methods.

fps_max 120 = bouncing from 7 to 10ms
afterburner capped to 120 = locked at 8.3ms

Do you have any idea what could be causing this? Any suggestions?

Thanks.

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RealNC
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Re: FPS capping question

Post by RealNC » 07 Sep 2014, 11:40

You don't need to cap your framerate if you have vsync disabled. With vsync off, the higher the frame rate, the less noticeable tearing will be (the distance between tear lines and the delta between the image above and below the tear lines will decrease as the frame rate increases; it's this decrease in distance and image difference that makes tearing less obvious with higher frame rates.)

You would use frame capping if you enabled vsync in order to reduce input lag. In that case, you would cap the frame rate slightly below the refresh rate. On 120Hz with vsync on, you would use "fps_max 119" in order to get less input lag (you can also use something like "fps_max 119.5" in Source engine games). A few frames are going to be doubled though, resulting in small micro-stutters. It's a trade-off between input lag and micro-stutter. If you don't want this trade-off, but want to get rid of both input lag *and* micro-stutter at the same time, you'd need a G-Sync monitor with a compatible NVidia GPU.
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Dew
Posts: 10
Joined: 07 Sep 2014, 11:19

Re: FPS capping question

Post by Dew » 07 Sep 2014, 12:02

Actually when I uncap the fps and it drops in the 120-180 range I see too much stuttering. I prefer the sharp tear over that.

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