What is VSYNC for dummies

[MasterLow]

Hi there I've been playing rainbow six siege and some others games and for a while now I've noticed this VSYNC 1 frame and 2 frame thing. I was wondering if i turn it on to 1 frame or 2 frame will the games performance. Also I would like to know the basics of what VSYNC is because I'm not very smart and my comprehension skills are not very high either so when i looked up what it was its kinda confusing as to what it is and still does? It said it had something to do with frame tearing? don't know what that is either... sorry for the dumb question.

[Guest]

Quote

 Vsync basically synchronizes your frames per second with your monitor refresh rate. It is not bad for any component and can reduce tearing in some instances. The problem is that it reduces your FPS rate if it is higher than your refresh rat

 

http://www.tomshardware.com/forum/358383-33-what-vsync-gaming

[Glenwing]

4 minutes ago, MasterLow said:

Hi there I've been playing rainbow six siege and some others games and for a while now I've noticed this VSYNC 1 frame and 2 frame thing. I was wondering if i turn it on to 1 frame or 2 frame will the games performance. Also I would like to know the basics of what VSYNC is because I'm not very smart and my comprehension skills are not very high either so when i looked up what it was its kinda confusing as to what it is and still does? It said it had something to do with frame tearing? don't know what that is either... sorry for the dumb question.

Ok so to start from the beginning....

 

Screens don't show continuous motion although they appear to be fluid, they just show a series of still images in fast sequence, fast enough that it appears like smooth video. Each still image is called a frame, typically screens show 60 frames every second (on a 60 Hz monitor). The graphics card generates the images, telling the monitor what color all the pixels should be for every frame. The graphics card may generate frames faster than 60 per second, but if the monitor only refreshes its image 60 times per second then only 60 will be shown, any more than that will be discarded.

 

When the screen updates its image to a new frame, it doesn't change all the pixels at the same time, it changes 1 row at a time and goes down each row from top to bottom, and it takes several milliseconds to change the entire screen to the new frame. The GPU also can't send the entire frame at once, it transmits as a continuous data stream, one pixel at a time. Since the GPU generates frames at its own speed, and may not be at a steady pace since some frames may take more calculations than others (depending on what's going on in the game), the GPU may finish generating a new frame at any time. If the monitor is in the middle of changing each row of pixels to a new frame, and the GPU finishes generating another new frame, the GPU will suddenly start sending the pixel data from that newer frame instead, and the screen will end up with the bottom half of the screen being from a different image than the top half. This is called tearing.

 

V-Sync limits the GPU's output so that it generates 1 frame and then stops working until the monitor is ready to refresh, instead of working on the next frame. When the monitor is ready, the GPU gives it the frame and then starts working on the next one, so that there is no possibility of finishing a frame in the middle of the monitor's refresh.

[Memorizer]

7 hours ago, Glenwing said:

Ok so to start from the beginning....

 

Screens don't show continuous motion although they appear to be fluid, they just show a series of still images in fast sequence, fast enough that it appears like smooth video. Each still image is called a frame, typically screens show 60 frames every second (on a 60 Hz monitor). The graphics card generates the images, telling the monitor what color all the pixels should be for every frame. The graphics card may generate frames faster than 60 per second, but if the monitor only refreshes its image 60 times per second then only 60 will be shown, any more than that will be discarded.

 

When the screen updates its image to a new frame, it doesn't change all the pixels at the same time, it changes 1 row at a time and goes down each row from top to bottom, and it takes several milliseconds to change the entire screen to the new frame. The GPU also can't send the entire frame at once, it transmits as a continuous data stream, one pixel at a time. Since the GPU generates frames at its own speed, and may not be at a steady pace since some frames may take more calculations than others (depending on what's going on in the game), the GPU may finish generating a new frame at any time. If the monitor is in the middle of changing each row of pixels to a new frame, and the GPU finishes generating another new frame, the GPU will suddenly start sending the pixel data from that newer frame instead, and the screen will end up with the bottom half of the screen being from a different image than the top half. This is called tearing.

 

V-Sync limits the GPU's output so that it generates 1 frame and then stops working until the monitor is ready to refresh, instead of working on the next frame. When the monitor is ready, the GPU gives it the frame and then starts working on the next one, so that there is no possibility of finishing a frame in the middle of the monitor's refresh.

I don't mean to change the topic but, I'm just wondering if, let's say you have a 144Hz monitor but your GPU can only run a game <144fps, would that cause tearing? Or would the display will show only 60Hz? 

(Pardon for the dumb question :/)

[Ordinarily_Greater]

3 minutes ago, Memorizer said:

I don't mean to change the topic but, I'm just wondering if, let's say you have a 144Hz monitor but your GPU can only run a game <144fps, would that cause tearing? Or would the display will show only 60Hz? 

(Pardon for the dumb question :/)

Wondering that too, thumbs up

[Glenwing]

6 minutes ago, Memorizer said:

I don't mean to change the topic but, I'm just wondering if, let's say you have a 144Hz monitor but your GPU can only run a game <144fps, would that cause tearing? Or would the display will show only 60Hz? 

(Pardon for the dumb question :/)

If your GPU generates frames at a lower rate than your monitor refreshes, your monitor still refreshes 144 times per second but some of those frames will be duplicates.

 

Tearing can happen at any framerate if the GPU and monitor are not synchronized with V-Sync or something similar.

[Memorizer]

1 minute ago, Glenwing said:

If your GPU generates frames at a lower rate than your monitor refreshes, your monitor still refreshes 144 times per second but some of those frames will be duplicates.

 

Tearing can happen at any framerate if the GPU and monitor are not synchronized with V-Sync or something similar.

Basically a 144Hz panel is useless if your GPU cannot run at least 144fps at most times?

[Glenwing]

10 minutes ago, Memorizer said:

Basically a 144Hz panel is useless if your GPU cannot run at least 144fps at most times?

Not at all, it's a lot smoother than 60 Hz, even if you're only getting say 100 fps.

[Memorizer]

Just now, Glenwing said:

Not at all, it's a lot smoother than 60 Hz, even if you're only getting say 100 fps.

Ah, so it's not a waste of money. Thank you for the help! I appreciate it

[GWARslave119]

On 5/25/2017 at 4:22 AM, Memorizer said:

Ah, so it's not a waste of money. Thank you for the help! I appreciate it

On 5/24/2017 at 8:20 PM, MasterLow said:

Hi there I've been playing rainbow six siege and some others games and for a while now I've noticed this VSYNC 1 frame and 2 frame thing. I was wondering if i turn it on to 1 frame or 2 frame will the games performance. Also I would like to know the basics of what VSYNC is because I'm not very smart and my comprehension skills are not very high either so when i looked up what it was its kinda confusing as to what it is and still does? It said it had something to do with frame tearing? don't know what that is either... sorry for the dumb question.

Theres a bit of misconception regarding vsync here, unless i read some replies wrong. I found this out a few years back. vsync doesnt limit the amiunt of frames ur gpu puts out, it just attempts to sync them with the refresh rate. Depending on the game engine, vsync can make the frametime/frames per second drop, even if you were getting well over your refresh rate beforehand. Its a case by case basis on whether to use it or not. A frame limiter, or frame cap, actually limits the frames your gpu puts out, so an ideal situation would utilize both without any perfomance or input loss. Using either one in the wrong situation wont be helpful at all.One way you can tell a frame limiter is enabled while vsync is on is if you watch ur gpu temp, it should drop a few degrees or so ionce you enable the limiter. For more info go to:

 

https://www.blurbusters.com/howto-low-lag-vsync-on/

 

as well as some of its related articles. It explains various things, as well as showing you how to determine ur true refresh rate, along with formulas (which i cant grasp how they were determined, but understabnd the jist) to where you minimize any input lag. example, the website it says to go to for your refresh rate, i set mine to 144hz,and whatever number is determined (i dont have it in front of me, im at work and just remember the outcome), subtract that by .01 which should be the input lag of things (?), and since 144fps isnt a feasable value in some newer games, i divide the answer by 2, which is 1/2 refrsh rate or every 2 frames, and so in RTSS RivaTuner (the recommeneded software with the least input lag, i set my /2 vsync to 71.987

[GWARslave119]

to put it shortly, vsync is used only if you have screen tearing, otherwise i dont think theres any reason, but i could be wrong. And a frame limiter or cap can relieve the workload of your gpu. Combined with vsync which is only taking in frames based on refresh rate, the 2 working in harmony theoretically  should apply.  Im bad at explaining things so sorry if i confused anyone

[Glenwing]

24 minutes ago, GWARslave119 said:

Theres a bit of misconception regarding vsync here, unless i read some replies wrong. I found this out a few years back. vsync doesnt limit the amiunt of frames ur gpu puts out, it just attempts to sync them with the refresh rate.

In traditional V-Sync (double buffered or triple buffered) it does limit the GPU output, as it will stop drawing once the buffers are full and wait for the vertical synchronization pulse. You can observe that GPU usage drops in these situations. In more modern variations like FastSync it will keep drawing continuously.