Question about 240hz refresh rate with vsync off

[darkbasicmaster]

I have a BenQ Zowie XL2546 240hz monitor, it has dyac technology. I play rainbow six siege, and I'm always trying to achieve the highest hz possible with the highest fps, vsync is off in-game and everything is on low. My question is, since the game is set on 240hz with vsync off, and sometimes my framerate doesn't always go above or match 240 fps for 240hz, will the amount of fps that I'm getting currently in game be the monitors refresh rate? Since it can't get up to 240fps for 240hz? Like Sometimes I dip to 180-190 fps, will that be the monitors refresh rate since vsync is off and since my monitor has dyac technology? (Idk if dyac helps my monitor do that at all, because I heard gsync does that with some monitors) Like 190 fps dip is 190hz, or a bad dip of 165 fps is 165 hz? Idk, I'm just wondering, thank you

 

[TheFluffyDog]

the monitors referesh rate is not dynamic. So it will always be 240hz.

DyAc is an image filter and post processing effect. it basically searches the frames for what the monitor thinks is motion blur, and then subtracts the "blur" providing enhanced contrast while the screen is moving quickly. Since the human eye is much more sentiive to contrast than the resolution, this will allow you to track a moving image better. Kind of like trying to see a dim light in a bright room. If the dim light is brighter, its easier to track.

 

[TheFluffyDog]

Honestly, if you go above 120hz the effects are not "visible" they are more related to the psychology of light rather than being able to "see" whats happening. There are many great studies that discuss how the brain interprets moving objects, and changing images. THere are also a great many studies that talk about how often eye receptors completely "refresh" depending on the level of epinephrine in the blood.

When it comes to monitors howvever, we are talking about a flashing image, and contrast and comparative brightness compared to the room around you are much more important than the difference between refresh rate and FPS.

RIght after brightness and contrast comes the actual refresh rate, and then to make it even "clearer" comes dynamic refresh rate and screen tearing. The reason screen tearing is such a big deal is that if it causes a larger "change" between frames. Without the tear, there are leass changes for the eye to track between 2 images and your eye can track better.

 

[derekullo]

With vsync on, if your monitor refreshes at 240 hertz and your fps is only 120 hertz, every frame gets shown twice.

With vsync off, if your monitor refreshes at 240 hertz and your fps is only 120 hertz, every whole frame should theoretically be shown twice but its possible only 75% of a frame could be shown.

This is what is known as page tearing.

 

[derekullo]

The above was a best case scenario where your fps was a multiple of your refresh rate.

When your fps is not a multiple of your refresh rate page tearing is much more noticeable.

It's possible that you won't notice the page tearing due to the high fps + native refresh rate.

But it would technically appear on a high speed camera.

 

[darkbasicmaster]

So since my monitors refresh rate isn't dynamic, it'll will always be 240hz even if i get like 190fps? And if so, say i get a constant 190 fps on a 240hz refresh rate, it'll just cause screen tearing? (I don't really notice any screen tearing when my fps dips down on rainbow six siege with the refresh rate set to 240hz) I also read somewhere on another thread that g-sync makes the monitors refresh rate dynamic? Like 175 fps is 175hz? or is there such a thing?

 

[derekullo]

You are absolutely correct.

When you only see a screen tear every 1/240th of a second it sort of blends in with the other frames.

As your fps gets lower screen tearing becomes more and more apparent as the time between frames becomes longer.

Hence the infamous 40 fps on a 60 hertz monitor with v-sync off.

 

[Solandri]

If vsync is off, the GPU just sends whatever it's drawn up to that point every time the monitor refreshes. So at 240 fps, each frame will contain completely new image info compared to the previous frame. If you dipped to 120 fps, the next frame would only contain a half screen of new image. The other half would be the remainder of the previous image, with a tear line at the transition. Likewise at 180 fps (3/4 240), 75% of the next frame would be new, the other 25% would be left over from the previous frame.

Gsync eliminates these partial draws and tear lines by only refreshing the monitor when a frame has been completed.

Normally your fps is not consistent and it deviates enough from the monitor's refresh rate so the tear line jumps to a seemingly-random location on the screen every frame. In that case it isn't very noticeable. But if your fps is consistent and very close to the refresh rate, the tear line will slowly crawl up or down the screen. Then it becomes really obvious.

It's tough to tell from the marketing blurb, but it sounds like Dyac is attempting to compensate for lag in pixel response to rapid changes in brightness, by overshooting. e.g. If a pixel is supposed to change from 0 (black) to 200 (light grey), at frame 1, it's only reached 170, at frame 2 it's reached 190, and at frame 3 it finally reaches 200. If my guess is right, Dyac is noticing the rapid change from 0 to 200, and overdrives the pixel instructing it to change to (say) 240 instead, making it reach 200 in the first frame.

 

[darkbasicmaster]

If vsync is off, the GPU just sends whatever it's drawn up to that point every time the monitor refreshes. So at 240 fps, each frame will contain completely new image info compared to the previous frame. If you dipped to 120 fps, the next frame would only contain a half screen of new image. The other half would be the remainder of the previous image, with a tear line at the transition. Likewise at 180 fps (3/4 240), 75% of the next frame would be new, the other 25% would be left over from the previous frame.

Gsync eliminates these partial draws and tear lines by only refreshing the monitor when a frame has been completed.

Normally your fps is not consistent and it deviates enough from the monitor's refresh rate so the tear line jumps to a seemingly-random location on the screen every frame. In that case it isn't very noticeable. But if your fps is consistent and very close to the refresh rate, the tear line will slowly crawl up or down the screen. Then it becomes really obvious.

It's tough to tell from the marketing blurb, but it sounds like Dyac is attempting to compensate for lag in pixel response to rapid changes in brightness, by overshooting. e.g. If a pixel is supposed to change from 0 (black) to 200 (light grey), at frame 1, it's only reached 170, at frame 2 it's reached 190, and at frame 3 it finally reaches 200. If my guess is right, Dyac is noticing the rapid change from 0 to 200, and overdrives the pixel instructing it to change to (say) 240 instead, making it reach 200 in the first frame.

That makes a whole lot more sense. Because I honestly don't see any tearing at all, so maybe dyac has something to do with it. Now is that what you're guessing? What you think is happening based on your knowledge of dyac? Because my frames jump fast and they vary from 170-240, and it goes up to 220-240 and down to 170 sometimes within a span of 1-2 seconds, it depends on where I look in the map.