Page 1 of 1

144hz and stutter

Posted: 29 Jan 2017, 10:20
by knypol
HI,

I have a fast question: will i get stuttering if i set refresh to 144Hz but ingame i will get only 120fps with VSYNC OFF? On 75Hz monitor when i dip below 75fps stutter is obvious.

Re: 144hz and stutter

Posted: 29 Jan 2017, 10:44
by Sparky
With vsync off you'll get tearing regardless of whether your framerate drops below refresh rate or not. I wouldn't call tearing stutter, but it can feel like stutter in some situations.

Re: 144hz and stutter

Posted: 29 Jan 2017, 10:56
by knypol
Tearing and stuttering are completelly different things...

Re: 144hz and stutter

Posted: 29 Jan 2017, 11:50
by Sparky
"Stuttering" is a very vague/generic term for a lack of fluid animation, and is used by many people to refer to problems that can be described much more specifically.

The reason I zeroed in on tearing is because you were asking about the impact of refresh rate, and specified vsync off.

Now, with vsync off, the age of image data being displayed varies by 1/refresh rate + 1/framerate. That's the entire impact your refresh rate has on smoothness with vsync off.

With vsync on it's a different story, as you do actually get smoother animation when vsync is limiting your framerate, but that comes with a lot of input lag.

Re: 144hz and stutter

Posted: 29 Jan 2017, 14:45
by Chief Blur Buster
TestUFO animations using the [/testufo] tags to show difference between stuttering and tearing:

Stuttering



Tearing



Tearing & Stuttering at same time


Re: 144hz and stutter

Posted: 29 Jan 2017, 15:08
by Falkentyne
Maybe my caffeine hasnt kicked in yet, but I'm looking at those animations at 60hz with blur reduction and I think I'm going to be sick...stuttering at such low framerates is bad.

BTW Chief please send me a PM

Re: 144hz and stutter

Posted: 02 Feb 2017, 14:23
by Chief Blur Buster
knypol wrote:HI,

I have a fast question: will i get stuttering if i set refresh to 144Hz but ingame i will get only 120fps with VSYNC OFF? On 75Hz monitor when i dip below 75fps stutter is obvious.
Addressing original question.

In regards to stutter, you will still get stutter. But the stutter will be less at higher frame rates.

120fps @ 144Hz will have half-amplitude stutter as 60fps @ 72Hz. Meaning object edges will 'vibrate' at only half amplitude. And stutter can be high-frequency to blend as motion blur.

You need framerate matching refreshrate, for the most stutter-free motion. Stutters are often also beat-frequency effects between framerate and refresh rate. At 273fps@240Hz can still be noticeed by human eyes, since that's a 33Hz beat frequency (273 minus 240 equals 33). It'll be much less visible, though.

Re: 144hz and stutter

Posted: 02 Feb 2017, 15:16
by Glide
FYI embedding those tests on the page makes it unreadable in Safari on iOS (iPhone).
The page just keeps scrolling down.

Re: 144hz and stutter

Posted: 02 Feb 2017, 15:39
by Chief Blur Buster
Interesting. It doesn't happen on my iPhone or iPad (iOS 10.2). What model iPhone and version of iOS are you using? Older iPhones had problems with these due to RAM limitations, especially when there was more than 1 test embedded. I'll have to debug that.

Re: 144hz and stutter

Posted: 03 Feb 2017, 14:49
by Glide
Chief Blur Buster wrote:Interesting. It doesn't happen on my iPhone or iPad (iOS 10.2). What model iPhone and version of iOS are you using? Older iPhones had problems with these due to RAM limitations, especially when there was more than 1 test embedded. I'll have to debug that.
It's an iPhone 7 Plus running 10.2.1