Fast Sync vs Vsync Smooth

No you.

Your theorycrafting is irrelevant when anyone with SLI can observe that:

1. Smooth VSync has double buffered VSync behavior when FPS drops below the monitor's refresh rate
2. Smooth has less input lag than standard VSync

 

Stay ignorant. Fool. I'm still waiting for that magical explanation of yours where you properly explain how exactly a two-card solution where each card is rendering a frame at the same time while a third frame is being displayed can be double-buffered. ROFL...

 

I'm the fool now? The basic fact of the matter is you've not even used SLI or Smooth VSync, so 1) you don't know what you're talking about and 2) you're not helping the OP. You just like finding things to nitpick and argue about. Keep derailing this thread, bruh.

 

I'm still waiting for that explanation. Take your time. You don't even understand fundamental mechanisms of graphical rendering.

 

Then keep waiting.

 

My last SLI setup was 980Tis.

There is nothing magical about your claimed setup.

 

Where did I claim there was any magic? It's simple observation. Smooth VSync drops FPS like double buffering below the monitor refresh rate. Smooth VSync has less input lag than standard VSync.

 

No it does not.

I've tested it before in a situation where both options(Vsync standard and smooth) can stay locked at 120fps under all circumstances.
Smooth vsync did not feel better than standard.

Smooth vsync is the same principle as standard vsync with the added detection/ability of preventing oscillation of frame rates and locks it to the lowest stable framerate.
The point of this is to reduce visible stutter as with SLI stutter is exuberated, which is quite an eyesore.

Other than that there is nothing inherently different.
Your claim that it is otherwise or that input lag is less is incorrect.

You haven't provided any legitimate proof

 

You have to compare Smooth vs standard at 60Hz. At 120Hz, the baseline VSync input lag is already much lower to begin with, as is the cumulative effect of 1 frame of input lag reduction.

You can do a search, many users know that Smooth is lower lag. If Smooth didn't reduce input lag compared to standard VSync, there would be no point for its existence because then all it does is reduce performance, since standard VSync in SLI is already triple buffered and doesn't suffer from those frame drops below the monitor refresh rate.

 

I can instantly tell vsync is on at 120hz, not necessary to retest anything.

Secondly, i already explained the sole purpose of Smooth vsync, to prevent stuttering from FPS oscillation.

Thirdly, double buffered in SLI mode is not happening.
SLI (specifically AFR mode) requires 3 buffers.
Forcing less buffers would seriously reduce effective performance of SLI.

Lastly, when you claim something you can't say "you can search for it"

Considering there's no articles that go into the extremes of your claims, I know you won't find legit proof.

 

I'm talking about the difference in input lag between VSync modes, not between VSync on vs off.

Such FPS oscillation does not happen in SLI, because SLI is inherently triple buffered as you yourself stated.

 

The point is I can notice any meaningful change of input lag, if it was a huge amount as you claim it would have been noticeable.

When SLI is active and natural frame rates of games are below the refresh rate of your monitor, traditional vsync forces frame rates to quickly oscillate between the refresh rate and half the refresh rate (for example, between 60Hz and 30Hz). This variation is often perceived as stutter. Smooth Vsync improves this by locking into the sustainable frame rate of your game and only increasing the frame rate if the game performance moves sustainably above the refresh rate of your monitor. This does lower the average framerate of your game, but the experience in many cases is far better.

Where do you see NVs claim that oscillation does not happen at all or that smooth vsync lowers input lag?

Regardless, effective total latency is higher using this as it locks FPS to a minimum sustainable factor of the refresh rate.

No point in beating a dead horse, if there was proof you would have provided it.
Since there is none, well you get the idea.

 

I never said it was a huge amount, just that it's more noticeable the lower your refresh rate is. For example, 1-2 frames of input lag reduction is almost nothing at 240Hz, but at 60Hz it's significant. This is why those low input lag VSync tricks you guys know about, like limiting to 0.007 FPS below your monitor's true refresh rate, and MPRF 1, while useful at 60Hz, have an essentially imperceptible benefit on a 240Hz display.

You should know this since you've used SLI, but I'll repeat myself: The oscillation does not occur since SLI is triple buffered

Look at this. VSync enabled at 60Hz, FPS stays in the 50-55 range with no oscillation between 30 and 60.

So that Nvidia page is wrong.

On a side note, here is another example of an Nvidia custhelp page that is wrong. Adaptive VSync (as well as Fast Sync) are hidden in NVCP on Optimus configurations, but they are still able to be used via Nvidia Profile Inspector.

 

Again, i can still notice a couple of frames of input lag even at 120hz.
I get what you're saying but the reduction isn't there considering the aforementioned.

Some form of oscillation always occurs on single gpu even with triple buffering or on SLI.
Oscillation of FPS or visible stutter.

Additional buffers halve the intervals of oscillation.
With SLI having variable frametimes it does not go 60 < 30 < 60(due to having 3 buffers), but it can fluctuate as 60 > anything 45 and higher >60 but it still does oscillate to some degree; especially regarding visible stutter.

I definitely recall seeing standard Vsync on SLI having some degree of fluctuations that did not happen with vsync off.
I've had 580 SLI, 680 SLI, TITAN SLI, etc and they've all had the same behavior.

Anyways, perceived smoothness will always be better when it's locked below the threshold of oscillation.
Besides that, another thing is possible is when you set a FPS limit slightly below fluctuating FPS; a stable constant framerate has a minor input lag reduction.

If for example game X your GPUs can achieve 300 fps regardless, on a 60hz monitor, having VSync on vs smooth vsync on will have zero difference in input lag.

There is nothing different about smooth vsync besides the ability to lock framerate interval below the threshold of fluctuating fps.
If it had other benefits, it definitely would have been marketed as such.

So to plainly put your theory to test, try VSync half refresh rate, at 30 fps in a game you get somewhere between >30 <60
Half refresh rate will lock it to 30fps where it should be stable.
Smooth Vsync ON will detect a stable 60fps is not possible and lock it to 30 fps.

In this case, the same effect is achieved.
You won't see any difference here.

Obviously in your case, use standard vsync + rtss fps limit set to the stable FPS smooth uses if it's not an exact fraction of 60.

As for the incorrect page, all it says is that it's not supported in the driver panel.
They never added it there, so it's not technically wrong.
Besides, it has no importance to anything else.

 

Wrong. VSync doesn't fluctate any more than no VSync. Here is VSync off. Frame rates look just like the previous VSync on video, except it can go above 60, like when looking at the sky.

There is a difference of input lag between standard and Smooth in that scenario, that's what I'm saying.

Again, I've shown that standard VSync doesn't fluctuate any more than no VSync when below 60.

Smooth on the other hand reduces performance and fluctuates/stutters more if you're hanging around but not perfectly locking at 60. For example:

Standard (50-60 FPS): https://streamable.com/vjy1b

Smooth (35-60 FPS): https://streamable.com/kg38j

 

There is fluctuations ,period. There is not an unlimited amount of back buffers when using SLI.
Game engines algorithm and implementation of vsync can vary quite a bit, especially when compared to driver forced vsync.

You seem hell bent on arguing exact framerates when I have already said fluctuations/oscillations are not limited to just framerates.(hence the point of smooth vsync)

You say there is no difference between vsync off and on, yet your comparisons are not the same.
The smooth vsync looks terrible, extremely jarring. Looking at standard Vsync at car with smooth it goes 50 > 35 fps. There's a significant increase in frame time which is not lowering input lag.

Anyways, you've said the same thing over and over, less input lag with smooth vsync with zero empirical data to back up the claim.
Think we are done here.

 

I didn't observe any difference between MW2's in-game VSync and standard Nvidia driver VSync. Smooth was compared to standard driver VSync, while VSync on vs. VSync off used the in-game setting (to prove that I wasn't bullshitting).

If they're not the same, then you tell me what difference you see, apart from VSync off being able to go above 60:
VSync on
VSync off

Exactly. Smooth is way worse than standard when dropping below the refresh rate.

Once again, Smooth has an input lag win over standard VSync only when the GPU is capable of constantly rendering frames in excess of the refresh rate, so that the frame rate locks at the refresh rate.

Smooth is better than standard when rendering above refresh rate. Standard is better than Smooth when rendering below refresh rate.

I don't have the testing equipment necessary for that, but I'm far from the only person making this claim. And if you can make claims such as "when you set a FPS limit slightly below fluctuating FPS, a stable constant framerate has a minor input lag reduction" and "I can still notice a couple of frames of input lag even at 120Hz" without empirical data or double-blind experimentation, then likewise I can also state that Smooth VSync has less input lag than standard VSync because that's the way it feels to me.

 

Just keep it by a feeling if you can't realy messure it that's oke

 

It just seems kind of hypocritical to me, is all.

 

Exactly that. Vsync + fps cap + 1 frame prerender limit.

Actually I lately set fps cap to Division vs. running just vsync + prerender 1.
Slight, but notable improvement to aiming responsiveness even with game's own fps limiter (75 fps cap).