Vsync with triple buffering question

[Genome852]

If you have a 60 hz monitor, then with double buffered vsync you can get 60 fps, 30 fps, 15 fps, etc.

But if you have triple buffering on and have, say, 45 fps, wouldn't that cause slight stuttering?

60 fps / 60 hz = 1 frame displayed per monitor refresh
30 fps / 60 hz = 1 frame displayed every 2 refreshes
45 fps / 60 hz = 3 frames displayed every 4 refreshes(?) Wouldn't this look like stutter? Would you get a screen tear with vsync off in this case?

 

[bystander36]

Yes, this is a known issue with v-sync. This is why Nvidia added adaptive v-sync.

 

[Liquid_Static]

Yes, you are in fact quite correct. Still a little better than being locked to 30...

 

[Cerb]

Wouldn't this look like stutter? Would you get a screen tear with vsync off in this case?

Yes and yes, and that's why 120Hz+ monitors are all the rage, these days.

Personally, I wish we could get an async display protocol set up, instead, to actually fix it, but that seems to be a pipe dream.

 

[Mr Expert]

Yes and yes, and that's why 120Hz+ monitors are all the rage, these days.

Personally, I wish we could get an async display protocol set up, instead, to actually fix it, but that seems to be a pipe dream.

60fps Vsync without tearing is better than higher framerates with tearing and inconsistant fram spikes inmo.

 

[Mr Expert]

If you have a 60 hz monitor, then with double buffered vsync you can get 60 fps, 30 fps, 15 fps, etc.

But if you have triple buffering on and have, say, 45 fps, wouldn't that cause slight stuttering?

60 fps / 60 hz = 1 frame displayed per monitor refresh
30 fps / 60 hz = 1 frame displayed every 2 refreshes
45 fps / 60 hz = 3 frames displayed every 4 refreshes(?) Wouldn't this look like stutter? Would you get a screen tear with vsync off in this case?

No it does not stutter.

 

[Cerb]

60fps Vsync without tearing is better than higher framerates with tearing and inconsistant fram spikes inmo.

I agree, but since LCDs don't fundamentally need a slow clock to sync to, wouldn't ti be great if a new frame could be sent at any time after the last frame, instead of exactly on every 60th of a second? Then, FI, 50 FPS could be truly 50 FPS, no tearing or frame display doubling, and only the max framerate would matter. We have the underlying technology (GPUs nor LCDs need such syncs), it's just that movies and TV shows are all the spec people seem to care about.

 

[Mr Expert]

I agree, but since LCDs don't fundamentally need a slow clock to sync to, wouldn't ti be great if a new frame could be sent at any time after the last frame, instead of exactly on every 60th of a second? Then, FI, 50 FPS could be truly 50 FPS, no tearing or frame display doubling, and only the max framerate would matter. We have the underlying technology (GPUs nor LCDs need such syncs), it's just that movies and TV shows are all the spec people seem to care about.

I prefer consitant 60fps locked. If I could afford 120fps then that would naturally be it.

 

[Cerb]

I prefer consitant 60fps locked.

But that's basically impossible, w/o playing old games, or console ports at low settings (despite having a fast CPU and GPU).

 

[toyota]

But that's basically impossible, w/o playing old games, or console ports at low settings (despite having a fast CPU and GPU).

no its very possible for all but a few games out there. I can easily adjust settings on my gtx660ti and most of the time games are on high or even very high. I certainly dont have to run any game at medium much less low settings to stay above 60fps at 1920x1080. and those games that cant stay at 60 fps the whole time on the settings I chose are because of the cpu at that point.

 

[Cerb]

...a CPU with a 33% overclock, making it 20%+ faster than any current mainstream CPU for most games. The GPU you can almost always get set to handle it, but I have yet to see a stock i5 that won't drop some frames on some games pretty regularly. M:LL, FI, will work fine at >60 FPS for maybe 80+% of the game, with low or medium settings, but there's going to be times when it drops a lot of frames, too, and does so regardless of those settings.

 

[PrincessFrosty]

If you have a 60 hz monitor, then with double buffered vsync you can get 60 fps, 30 fps, 15 fps, etc.

But if you have triple buffering on and have, say, 45 fps, wouldn't that cause slight stuttering?

60 fps / 60 hz = 1 frame displayed per monitor refresh
30 fps / 60 hz = 1 frame displayed every 2 refreshes
45 fps / 60 hz = 3 frames displayed every 4 refreshes(?) Wouldn't this look like stutter? Would you get a screen tear with vsync off in this case?

It's 60fps, 30fps, 20fps...etc, it doesn't half each time, it's (1/n) * (frame rate)

With triple buffering you get a higher frame rate usually but the timing between frames can be extremely uneven, perceptive people will be able to notice it, it looks something a bit like micro-stutter which is a similar problem but caused by using multiple GPUs to alternate frame rendering.

You ALWAYS screen tear with vsync off, there's a lot of misinformation floating around that you only tear at frame rates below or above your refresh rate, it's all false, you tear at any frame rate with vsync off.

Even if you have exactly 60fps on a 60hz monitor you will still (likely) tear, because it's not just about matching the right speed but the synchronicity of the 2 speeds.

 

[PrincessFrosty]

I agree, but since LCDs don't fundamentally need a slow clock to sync to, wouldn't ti be great if a new frame could be sent at any time after the last frame, instead of exactly on every 60th of a second? Then, FI, 50 FPS could be truly 50 FPS, no tearing or frame display doubling, and only the max framerate would matter. We have the underlying technology (GPUs nor LCDs need such syncs), it's just that movies and TV shows are all the spec people seem to care about.

John Carkmack in his latest Quakecon Keynote talk actually touched on this and talked about pushing for standards for an extra bit (channel) to the monitor to show support for this, I think that's just something that he thought it would be nice to have, I don't expect to see anything come of it. It would help reduce latency a lot and basically solve tearing. Although there would have to be a minimum frame render time because LCDs have fairly slow pixel response times the primary factor stopping them getting faster than 120hz.

But that's basically impossible, w/o playing old games, or console ports at low settings (despite having a fast CPU and GPU).

I have a 2600k@4.9Ghz and SLI 580's overclocked a little, a vast majorety of games will pull 100+fps in 1080p, feels really sharp on my 120hz panel, sometimes you have to sacrifice absolute max settings but that's not really a problem.

There's this really huge stigma in gaming where graphics are put ahead of everything, most of our console games are made for 30fps which is completely disgusting, a lot of PC gamers are happy with 30ish, some prefer 60fps which is commendable but few demand anything in the 100fps region. But when you realize that it positively effects your game play experience to have much tighter feedback you become less stubborn about dropping the quality sliders a few notches to achieve a better frame rate.

This is what I like about Carmack, he pushed for 60fps in Rage on the consoles, it's one of the few AAA 3D games on the consoles to run at a solid 60fps, he had to fight almost everyone on the development team to keep that the standard during development, but they did it and it looks AND runs fantastic.

 

[Lonbjerg]

John Carkmack in his latest Quakecon Keynote talk actually touched on this and talked about pushing for standards for an extra bit (channel) to the monitor to show support for this, I think that's just something that he thought it would be nice to have, I don't expect to see anything come of it. It would help reduce latency a lot and basically solve tearing. Although there would have to be a minimum frame render time because LCDs have fairly slow pixel response times the primary factor stopping them getting faster than 120hz.



I have a 2600k@4.9Ghz and SLI 580's overclocked a little, a vast majorety of games will pull 100+fps in 1080p, feels really sharp on my 120hz panel, sometimes you have to sacrifice absolute max settings but that's not really a problem.

There's this really huge stigma in gaming where graphics are put ahead of everything, most of our console games are made for 30fps which is completely disgusting, a lot of PC gamers are happy with 30ish, some prefer 60fps which is commendable but few demand anything in the 100fps region. But when you realize that it positively effects your game play experience to have much tighter feedback you become less stubborn about dropping the quality sliders a few notches to achieve a better frame rate.

This is what I like about Carmack, he pushed for 60fps in Rage on the consoles, it's one of the few AAA 3D games on the consoles to run at a solid 60fps, he had to fight almost everyone on the development team to keep that the standard during development, but they did it and it looks AND runs fantastic.

You mean vast amout of console ports rigt?
Because dedicated PC games....not so much:
http://www.hardocp.com/article/2011...pu_gameplay_performance_review/2#.Ugij-XDU99M

 

[PrincessFrosty]

Yeah sure, MOST games on the PC these days are multi-platform games, there is a few dedicated PC games, Arma II, The Witcher 2 and a few others that have some really serious high end graphics or CPU requirements.

They are an insignificant few among the slew of multi-platform games, and again dropping a few settings will often help bring that frame rate back up.

That hardocp.com review is dealing with triple 1080p monitor configurations, I'm talking about a single 1080p 120hz panel, triple monitor rigs are also rare as a percentage of total users/configurations.

 

[Lonbjerg]

Yeah sure, MOST games on the PC these days are multi-platform games, there is a few dedicated PC games, Arma II, The Witcher 2 and a few others that have some really serious high end graphics or CPU requirements.

They are an insignificant few among the slew of multi-platform games, and again dropping a few settings will often help bring that frame rate back up.

That hardocp.com review is dealing with triple 1080p monitor configurations, I'm talking about a single 1080p 120hz panel, triple monitor rigs are also rare as a percentage of total users/configurations.

So youwere talking console games ports/crosplatform titles not pure PC games, gotcha.

 

[PrincessFrosty]

My statement was made with a scope that refers to all games on the PC...not sure why this is unclear.

 

[Lonbjerg]

There is a clear distinction between PC games and crossplatform titles/ports.
PC games don't suffer form the low specs of consoles...they don't have to be dumbed down to oblivion to run.

Hence why we have true PC games like the ARMA series.

 

[PrincessFrosty]

I understand there's a distinction, but it doesn't invalidate what I said.

"True PC games" account for an almost imperceptibly small percentage of all development in modern gaming where performance could be considered an issue. Which is why I qualified my statement as "the vast majority".

 

[Lonbjerg]

I understand there's a distinction, but it doesn't invalidate what I said.

"True PC games" account for an almost imperceptibly small percentage of all development in modern gaming where performance could be considered an issue. Which is why I qualified my statement as "the vast majority".

There is a clear distinction.
Games like ARMA 3 or Rome Total War 2 will never come to consoles.
The pure PC games also look lightyears ahead of the ports/cross.

I didn't buy a PC to game consoleports....did you?

 

[PrincessFrosty]

Right, I've already agreed, there's a distinction. It just doesn't have any relevance to what I said.

I bought a PC to get the best gaming experience possible because only PCs can deliver that, but the vast majority of games available are multi-platform games, whether or not the game is multi-platform or not is not really very important to me, it's how good the game is that matters to me.

Sometimes multi-platform games look outdated, sometimes they look bad ass because the devs spent some extra time on the PC version, it's a mixed bag.

 

[Mushkins]

Right, I've already agreed, there's a distinction. It just doesn't have any relevance to what I said.

I bought a PC to get the best gaming experience possible because only PCs can deliver that, but the vast majority of games available are multi-platform games, whether or not the game is multi-platform or not is not really very important to me, it's how good the game is that matters to me.

Sometimes multi-platform games look outdated, sometimes they look bad ass because the devs spent some extra time on the PC version, it's a mixed bag.

Dont waste your time feeding the troll He's going to keep up his "but PC master race blah blah blah" no matter what you say, ignoring the fact that there's a lot of PC-only games that run like crap because they're poorly coded and it has nothing to do with consoles.

Back on topic, you don't even need a top end single GPU or top end CPU to keep a steady 60 FPS or above in most well made PC games with the settings turned up today. Yes, sometimes you'll get a dropped frame or two, but a lot of times that happens regardless of your setup because its a game code issue, there's a lot of factors that ultimately go into drawing and displaying those frames in a timely manner and any of them could be the cause of a dropped or slow frame in any given situation.

At least to me, a consistent tear-free 60FPS gives me a better experience than jumping all over the place between 80FPS and 200FPS and 45FPS. Yes, your response time is fractions of a second more accurate, but sudden big increases or drops in FPS can be downright disorienting at times and screen tearing drives me nuts. Imagine watching a movie where the top half of the screen kept stuttering half a frame ahead cutting the actors in half? But i'm not a hardcore competitive FPS player and that fraction of a second does not affect my gameplay either, one size does not fit all.

 

[MTDEW]

If you have a 60 hz monitor, then with double buffered vsync you can get 60 fps, 30 fps, 15 fps, etc.

But if you have triple buffering on and have, say, 45 fps, wouldn't that cause slight stuttering?

60 fps / 60 hz = 1 frame displayed per monitor refresh
30 fps / 60 hz = 1 frame displayed every 2 refreshes
45 fps / 60 hz = 3 frames displayed every 4 refreshes(?) Wouldn't this look like stutter? Would you get a screen tear with vsync off in this case?

Yes, you are in fact quite correct. Still a little better than being locked to 30...

Now I admit, that this is the part I've never fully understood about playing with v-sync ON.
If you're averaging 40fps - 50fps, wouldn't it run smoother to just lock it at a constant 30fps?
Or does it still give the "perception" of a smoother gameplay experience allowing the frame-rate to fluctuate at 40-50fps?

I personally don't disable v-sync because i hate tearing and really only play SP games anyway.
And i regularly play games where I'm not able to achieve a consistent 60fps and fluctuate in the 40fps - 50fps ranges.
So what exactly is the best/smoothest settings combination for this type of scenario?

 

[PrincessFrosty]

It depends what you mean by smooth, it is used in 2 contexts here.

The first context - smooth is the difference in frame times between each frame, so if you have a frame take 10ms to render, and the next is 10ms, and then 10ms and so on, you might describe that as a smooth distribution. Compared to say 8ms then 12ms then 14ms then 7ms.

The second context - the number of frames per second, when you have to represent the illusion of motion with discreet snapshots in time, the more snapshots per second the smoother that movement will appear to observers.

In some senses, as well as eliminating tearing Vsync trades one kind of smooth for another, it trades away frequency of updates (the frame rate), for regularity of updates, so each update happens at a set interval 16.666ms in the case of 60fps.

This happens because vsync could be thought of as sacrificing speed over accuracy, it essentially says "if the next frame is ready before the monitor is ready, then delay it from being displayed until we're ready"

This is where the idea of smoothness and stuttering become a bit nebulous on forum discussions because it's often hard to identify which kind of stuttering people are talking about, it's something that crops up as an issue with multi-GPU and so called micro-stuttering where the method of increasing frame rate also tends to cause irregular frame distribution/frequency, so despite having a much higher overall average frame rate, games still appear to "stutter".

 

[BrightCandle]

Now I admit, that this is the part I've never fully understood about playing with v-sync ON.
If you're averaging 40fps - 50fps, wouldn't it run smoother to just lock it at a constant 30fps?
Or does it still give the "perception" of a smoother gameplay experience allowing the frame-rate to fluctuate at 40-50fps?

pcper.com has some really nice videos where they do exactly this, they compare vsync on and off and 30 fps locked. The end result is that 30 fps consistently (capped by the driver) is actually smoother than having the frame rate vary in the 40's. Its a really interesting set of videos, well worth digging out if you haven't seen them. My only warning is that once you can see this stutter and you can compare it you will start to see it in games, so if you are happy today as you play it might be better not to see the stutter that vsync causes at anything but 60fps.