nvidia Fast Sync not working?

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Gawd
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I have Fast Sync enabled globally, but in some games it doesn't seem to be working. Have any of you seen this?
 
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First of all, if you set a global override in the control panel, shouldn't that override whatever the game is set to?

Second, it's not working like that. With Fast Sync enabled globally, in Black Ops 2 I get tons of lag if Vsync is enabled in-game, and tearing with no lag if Vsync is disabled in-game.
 
The way I understood it, you should leave VSync Off in the game settings. But now that I'm looking for official confirmation, it's hard to find. All I can see is a Reddit post from a few months ago, and my own experience playing with it. The lag with VSync On sounds right, as it should have the same amount of input lag as with standard VSync. However, I do wonder about tearing with VSync Off. I tried a number of games, and I did not notice any tearing with Fast Sync On and VSync Off. Can you try a game other than Black Ops 2?
 
First of all, if you set a global override in the control panel, shouldn't that override whatever the game is set to?

Second, it's not working like that. With Fast Sync enabled globally, in Black Ops 2 I get tons of lag if Vsync is enabled in-game, and tearing with no lag if Vsync is disabled in-game.
You'll still get tearing with Fast Sync if your framerate is below your monitor's refresh rate. It operates without any syncing in that state. Above your monitor's refresh rate the video card is still rendering as fast as possible, but the driver is discarding frames before hitting the display so that it is only showing frames as quickly as the monitor refreshes. In short: if you don't want any tearing at all under your monitor's refresh rate then you still need to use V-Sync with triple buffering.
 
Sorry, my original statement wasn't right. Fast Sync wasn't set globally like I had thought (maybe a driver update defaulted it back).

Diablo 3 used to crash in-game when changing the Vsync setting with Fast Sync enabled globally, but either Blizzard or Nvidia must have patched that since it no longer does. The reported framerate in the game changes based on the in-game Vsync checkbox, so it's still affecting something in spite of Fast Sync enabled globally. I need to do some more tests with more games.
 
The way I understood it, you should leave VSync Off in the game settings. But now that I'm looking for official confirmation, it's hard to find. All I can see is a Reddit post from a few months ago, and my own experience playing with it. The lag with VSync On sounds right, as it should have the same amount of input lag as with standard VSync. However, I do wonder about tearing with VSync Off. I tried a number of games, and I did not notice any tearing with Fast Sync On and VSync Off. Can you try a game other than Black Ops 2?

Correct. In-game settings take priority.
 
Sorry, my original statement wasn't right. Fast Sync wasn't set globally like I had thought (maybe a driver update defaulted it back).

Diablo 3 used to crash in-game when changing the Vsync setting with Fast Sync enabled globally, but either Blizzard or Nvidia must have patched that since it no longer does. The reported framerate in the game changes based on the in-game Vsync checkbox, so it's still affecting something in spite of Fast Sync enabled globally. I need to do some more tests with more games.

Diablo 3 has always done things differently. As I recall, it doesn't work with gsync, either. So I wouldn't use Diablo 3 as an indicator of whether fast sync is working, as it just likely isn't supported.
 
I tested 4 more games. In every case, setting the Nvidia control panel global tab for Vertical sync to "Fast" overrides whatever the in-game Vsync setting is. This is good.

Oblivion: there is no in-game setting. Setting the control panel to "Use application" causes vsync and lag. Setting Fast Sync cause vsync and no lag.

Unreal Tournament 3: With "Use application", the game always has low-lag and tearing regardless of the in-game Vsync checkbox! Fast Sync causes no tearing and no lag.

Black Ops 1 and Pool Nation: With "Use application", the in-game vsync checkbox works as expected. Fast Sync overrides whatever that checkbox is set to.
 
Perhaps the global setting does that. Per-game profile, it may be game-dependent, as Overwatch (for sure) and Dying Light (IIRC) don't follow the profile-selected Sync option unless VSync is disabled.
 
If you want to use Fast Sync, then you enable it in the Nvidia Control Panel but inside the game settings VSync should be OFF.

Depends on the game. World of Warcraft, for example, has issues with 3rd party injected Vsync options. In order for Fast Sync or Adaptive Sync to work with World of Wacraft (since the Legion patch), in-game Vsync must be turned ON. It's counter intuitive, but this is currently the case.


You'll still get tearing with Fast Sync if your framerate is below your monitor's refresh rate. It operates without any syncing in that state. Above your monitor's refresh rate the video card is still rendering as fast as possible, but the driver is discarding frames before hitting the display so that it is only showing frames as quickly as the monitor refreshes. In short: if you don't want any tearing at all under your monitor's refresh rate then you still need to use V-Sync with triple buffering.


This is incorrect. Fast Sync eliminates tearing at all times. Above the refresh rate works as you describe it. Below the refresh rate it essentially is supposed to function like standard Vsync. It doesn't in my experience. Something is different, but it's definitely tear-free.

If your experience is different, then perhaps its behavior is different in different games?
 
Thanks Daniel_Chang . The games I tried seemed to work with VSync Off, but there are always odd cases.

In my experience, Fast Sync eliminated tearing regardless of frame-rate (both below or above refresh rate).

My initial assumption was that Fast Sync should function like VSync On when below refresh, but it was not exactly this. I recorded some slow-motion videos and Fast Sync definitely had erratic motion when frame-rates were close to refresh rate give or take. So there would be either a jump or a hitch every second or so. While playing, it appeared smooth to me, but looking at the recording afterwards it was clear the motion was irregular. At 90fps and higher, it did appear smooth. And once you got to around 200fps, you could really feel the difference in terms of reduced input lag and the experience was smooth.
 
My initial assumption was that Fast Sync should function like VSync On when below refresh, but it was not exactly this. I recorded some slow-motion videos and Fast Sync definitely had erratic motion when frame-rates were close to refresh rate give or take. So there would be either a jump or a hitch every second or so. While playing, it appeared smooth to me, but looking at the recording afterwards it was clear the motion was irregular. At 90fps and higher, it did appear smooth. And once you got to around 200fps, you could really feel the difference in terms of reduced input lag and the experience was smooth.

My experience is similar. With World of Warcraft and Vsync on, dipping below 60fps introduces stutter, but it's a relatively linear progression from 59-30fps. With Fast Sync instead, it's hard to notice at 56-60fps, noticeable at 51-56fps, and pure shit below 50fps (maybe a tad lower).
 
Wait, doesn't anything below 60fps with Vsync or Fast Sync cause 30fps, since that's the next-fastest multiple of your monitor?

I don't have Overwatch or WoW to be able to test Fast set globally. Can anyone test that now? Since Diablo 3 now seems to honor the global setting, I wonder if nvidia might have changed something to fix it for all games.
 
Wait, doesn't anything below 60fps with Vsync or Fast Sync cause 30fps, since that's the next-fastest multiple of your monitor?

I don't have Overwatch or WoW to be able to test Fast set globally. Can anyone test that now? Since Diablo 3 now seems to honor the global setting, I wonder if nvidia might have changed something to fix it for all games.

only if you are using double buffers because you run out of buffers to render to and the gpu stalls. 1 buffer is beeing used to give info for the monitor to refresh. and the 2nd buffer is the next to show. GPU has no more palce to render a frame.

With triple buffering and fast sync ( which is basicly ttripplebuffering invisible for the software) there is no vsync drops cause you gpu can still continue rendering on the third buffer. what fasync does it it continues rendering evne when the third buffer is full by using the htirdbufer as next inline to be shown. and then uses the 2nd buffer to continue renderigng. that why you can have higher fps than sync.
once you monitr refrsh scycle is over it jsut swap in the newest finish buffer to be the buffer the monitor gets the pictures from.
 
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