Vsync

[firewings]

hi ;

 

what's a difference between Vsync on or off .

[deflag]

Vsync limits your FPS to 60 max. LCD monitors have a standard refresh rate of 60 or 59Hz (FPS) if you play a game with more than 60 FPS you can get screen tearing which can look quite ugly so Vsynk helps with this isue.

 

Hope this helps

[Insanatrix]

Vsync actually sync's your FPS to your monitor's refresh rate. Not just 60fps. meaning it displays 1 frame per refresh cycle. Just limiting your FPS to 60 fps or under is not the same as having Vsync enabled. Tearing is simply the simulator drawing and displaying a frame in between refresh cycles of your monitor. You can get tearing with 30fps, there is just less chance for it with lower frame rates as there is less of a chance for a frame to be rendered in the middle of a refresh cycle.

[Fakum]

so if we have LCD, it benefits us to enable it correct? Any negative impacts doing so? And how do you set it in the 1.0.8 version exactly? I have seen spotty postings about having to do it in one og the .lua files? Thanks

[Insanatrix]

graphics.cfg file under the config folder.

 

under DisplayMode you will see

 

{

resolution = {800, 600};

bpp = 32;

fullscreen = 0;

aspect = 1.333333333;

sync = true;

Interface

 

Make sure sync = true is set and Vsync should be enabled.

[hassata]

so if we have LCD, it benefits us to enable it correct?

 

Only if you're getting more that 60 FPS most of the time. You're better off (imho) lmiting fps to avoid dip[s and spike for a smother experience. You can do that in the graphics.lua as well with the maxpfs line. I have maxfps = 30.

[Insanatrix]

You can get tearing above below and at 60fps steady. Vsync sync's the rendering of frames to your monitor's refresh rate. I only get like between 16-38fps and get tearing like crazy without Vsync enabled.

[PhoenixBvo]

Some time ago I made the attached graphic which explains V-sync in connection with either double buffering (the standard) or triple buffering.

The checkered boxes are the frame buffers. One is where the GPU writes to and the other is where the monitor reads from. In reality the buffers are swapped rather than copied, but for the purpose of understanding the concept it suffices to imagine them as such. Without V-sync the GPU buffer is copied once the monitor completes a frame. Most likely the GPU will be in the middle of writing a new frame to it's buffer however, causing a partial new frame to be displayed with the upper half belonging to a newer timestep and the lower being from an older time. This is the tearing which you see. V-sync only copies a frame when both the GPU and monitor are ready and holds the GPU when the monitor is still in the middle of a frame.

 

It may be a bit confusing to bring the issue of triple buffering into the discussion, but fact is that V-Sync with double buffering will cause your graphics card to sit around waiting for a percentage of time (even if it's slower than the monitor refresh rate). This is what triple buffering solves.

[REL]

Some time ago I made the attached graphic which explains V-sync in connection with either double buffering (the standard) or triple buffering.

The checkered boxes are the frame buffers. One is where the GPU writes to and the other is where the monitor reads from. In reality the buffers are swapped rather than copied, but for the purpose of understanding the concept it suffices to imagine them as such. Without V-sync the GPU buffer is copied once the monitor completes a frame. Most likely the GPU will be in the middle of writing a new frame to it's buffer however, causing a partial new frame to be displayed with the upper half belonging to a newer timestep and the lower being from an older time. This is the tearing which you see. V-sync only copies a frame when both the GPU and monitor are ready and holds the GPU when the monitor is still in the middle of a frame.

 

It may be a bit confusing to bring the issue of triple buffering into the discussion, but fact is that V-Sync with double buffering will cause your graphics card to sit around waiting for a percentage of time (even if it's slower than the monitor refresh rate). This is what triple buffering solves.

 

So it's good or bad for FPS?

[PhoenixBvo]

Well, V-sync limits the possible frame rates to integer fractions (1/1, 1/2, 1/3 etc.) of the monitor refresh rate. If your graphics card is fast enough to reach the monitor refresh rate (e.g. 60 Hz) V-sync will not reduce the effective (or perceived)frame rate. However, when the GPU dips just slightly under the monitor refresh rate, V-sync immediately halves the frame rate (e.g. 30 Hz).

 

So, V-sync may result in lower frame rates and not in higher ones. However, the human perception works such that changes in frame rate are much more noticable than constant lower frame rate. So if your frame rate without V-sync remains within the range between two integer fractions of the monitor refresh rate (e.g. between 60 and 30 Hz) it would result in a smoother experience to turn V-sync on, even though the resulting frame rate is lower (namely constant at 30 Hz in this example).

 

Does that answer your question? :smartass:

 

EDIT: That is, assuming we are talking about double buffered V-sync. But that's effectively the only option available with DirectX. Triple buffering decouples GPU and monitor rates, but introduces more delay. Everything comes at a price...

Edited June 9, 2011 by PhoenixBvo
Addition

[scheffchen]

Well, V-sync limits the possible frame rates to integer fractions (1/1, 1/2, 1/3 etc.) of the monitor refresh rate. If your graphics card is fast enough to reach the monitor refresh rate (e.g. 60 Hz) V-sync will not reduce the effective (or perceived)frame rate. However, when the GPU dips just slightly under the monitor refresh rate, V-sync immediately halves the frame rate (e.g. 30 Hz).

 

So, V-sync may result in lower frame rates and not in higher ones. However, the human perception works such that changes in frame rate are much more noticable than constant lower frame rate. So if your frame rate without V-sync remains within the range between two integer fractions of the monitor refresh rate (e.g. between 60 and 30 Hz) it would result in a smoother experience to turn V-sync on, even though the resulting frame rate is lower (namely constant at 30 Hz in this example).

 

Does that answer your question? :smartass:

 

EDIT: That is, assuming we are talking about double buffered V-sync. But that's effectively the only option available with DirectX. Triple buffering decouples GPU and monitor rates, but introduces more delay. Everything comes at a price...

 

So the best option for a tearing free image display would be a superfast graphic card (being able to produce 70fps) with a 60hz monitor and vsync enabled, respectively the same graphic card with a 120hz monitor but vsync disabled. Correct?

Ooor: use 2 of the superfast gfx-cards on the 120hz monitor with vsync enabled. :D

[PhoenixBvo]

So the best option for a tearing free image display would be a superfast graphic card (being able to produce 70fps) with a 60hz monitor and vsync enabled, respectively the same graphic card with a 120hz monitor but vsync disabled. Correct?

Ooor: use 2 of the superfast gfx-cards on the 120hz monitor with vsync enabled. :D

 

Not correct, I'm afraid. Your second option with a 120Hz monitor and around 70Hz capable graphics card without V-sync would still produce tearing in the image, because the new monitor frames will be swapped at time instances when the graphics card is in the middle of producing its next frame. Without V-Sync image tearing will always be a possible annoyance.

[Bucic]

Well, V-sync limits the possible frame rates to integer fractions (1/1, 1/2, 1/3 etc.) of the monitor refresh rate.

The matter of vsync is simple when it comes to DCS and it has been long time established that:

1. Not in DCS Black Shark In DCS BS Vsync is practically a win-win option.
   
2. Tripple buffering does nothing for DCS BS because it's not even needed
   

 

Most probably applies to DCS Warthog as well.

 

 

 

Summary with all the necessary links: http://forums.eagle.ru/showthread.php?p=994066#post994066

with explanatory figures such as this one

 

Direct links to the topics with definitive explanations of vsync and tripple buffering:

Maxfps not working http://forums.eagle.ru/showthread.php?t=49651

Why was Vsync needed? http://forums.eagle.ru/showthread.php?t=49448&highlight=vsync+integer&page=2

Edited June 9, 2011 by Bucic

[REL]

Yes! thanks PhoenixBvo

[PhoenixBvo]

The matter of vsync is simple when it comes to DCS and it has been long time established that:

1. Not in DCS Black Shark In DCS BS Vsync is practically a win-win option.
   
2. Tripple buffering does nothing for DCS BS because it's not even needed
   

Most probably applies to DCS Warthog as well.

 

 

 

I believe that graphic shows triple buffered V-sync (if indeed it is not just an fps cap). There is no way (that I know of) a double buffer system can produce smooth frame rate changes with V-sync. Please enlighten me how such result would be produced if it actually is double buffered. (See my diagram for the underlying functioning of V-sync)

 

If your graph is indeed the result of a DCS:BS session with V-sync enabled, then I assume the DCS application has a way of enabling triple buffering...

[Bucic]

If your graph is indeed the result of a DCS:BS session with V-sync enabled, then I assume the DCS application has a way of enabling triple buffering...

This is exactly what my posts say - forcing tripple b. is obsolete as DCS has it's own way. There's no point going into tech details so I don't. I simply enjoy and spread the word :)

[Shootist]

It's all gobbledygook to me but in the interest of getting all I can get out of the game, you guys can see my stats. Vsync is off. I've got an almost unseeable perception of stutter. Should I leave it off or flip it on? Probably wouldn't make a bit o diff but I am curious. Oh ya, I've got a fairly dated LGFlatron L222WT screen.

[Bucic]

It's all gobbledygook to me but in the interest of getting all I can get out of the game, you guys can see my stats. Vsync is off. I've got an almost unseeable perception of stutter. Should I leave it off or flip it on? Probably wouldn't make a bit o diff but I am curious. Oh ya, I've got a fairly dated LGFlatron L222WT screen.

Definitely on. I can imagine that only crawling systems can benefit from Vsync off for DCS.

 

Vsync works better than FPS limiter in the field of making everything smooth, plus it gets rid of tearing. Apart from the perception there are two ways to test Vsync advantages on the spot:

- quickly move your head camera (rotate) horiz. - you won't see tearing on canopy frames etc.

- even better one: try to identify a ground unit (or another detail) visually from close distance while flying by it. Vsync makes it easier! Without Vsync - almost impossible.

[Shootist]

Ahh. Thanks for that.

[Eggcake]

Well, it's really bad if you switch often between 30 and 60 fps for example (so if you get "around" 60 FPS). It feels like the game slows down and speeds up again. It's not that bad in DCS though I have to admit.

 

I rarely get >60FPS with my settings. Im testing VSync On right now. To be honest, I didn't "feel" any difference (my FPS were always at 30, sometimes they dropped). So if I don't feel a big difference but the tearing is gone --> VSync on. But I think I need more testing :)

Right now I'm still at 1650x1050 but I'll switch to 1920x1080 this weekend - I probably have to lower the graphics settings. "Highest" is too much for a 5850 it seems.

It's a bit Off Topic but what settings do you think can be lowered with the "least" impact on graphics quality?

Edited June 9, 2011 by Eggcake

[Bucic]

Well, it's really bad if you switch often between 30 and 60 fps

Have you bothered to read what has been said about vsync in DCS in the end?

[Eggcake]

I actually did but didn't quite get it. But I think I understand now :)

[Laud]

It's a bit Off Topic but what settings do you think can be lowered with the "least" impact on graphics quality?

 

OT answer: Try to set water from high to medium first. It has a noticeable impact on performance, while still looking good enough (my opinion).