-
Hey, guest user. Hope you're enjoying NeoGAF! Have you considered registering for an account? Come join us and add your take to the daily discourse.
Nvidia FAST Sync, what pc gamers have needed for decades
- Thread starter ACH1LL3US
- Start date
Like I said in another thread, it's "just" triple buffering.
Actual triple buffering as you can see described in textbooks from the 90s, not what has come to be called "triple buffering" recently but is really just a 3-buffer queue.
That said, it's a very good thing to get an option for it in the driver, since on a modern system it's basically impossible to enforce real triple buffering in fullscreen mode.
Actual triple buffering as you can see described in textbooks from the 90s, not what has come to be called "triple buffering" recently but is really just a 3-buffer queue.
That said, it's a very good thing to get an option for it in the driver, since on a modern system it's basically impossible to enforce real triple buffering in fullscreen mode.
It's just baffling to me why it has taken this long to get this basic feature back and why a GPU vendor had to implement it in their driver.
The reason we have this silly Fast Sync nomenclature is because the user base has long since lost visibilty of the concept. This is just triple buffering and you can read about it in this anandtech article from 7 years ago.
Either developers mostly didn't think it was important or DirectX makes it difficult to achieve, which I find hard to believe.
I suppose most developers used DirectX's buffer queue and didn't think anything more of it. Backpressure is what causes shitty latency on 60Hz displays with Vsync enabled.
So boo to Nvidia for not just calling this what it is, but yay for doing it and giving users more options. I've never owned a 60Hz LCD monitor and I don't need to play games at 300fps, so it doesn't affect me much. I suppose it might be good for latency improvement in the games where I use Vsync and monitor backlight strobing.
The reason we have this silly Fast Sync nomenclature is because the user base has long since lost visibilty of the concept. This is just triple buffering and you can read about it in this anandtech article from 7 years ago.
Either developers mostly didn't think it was important or DirectX makes it difficult to achieve, which I find hard to believe.
I suppose most developers used DirectX's buffer queue and didn't think anything more of it. Backpressure is what causes shitty latency on 60Hz displays with Vsync enabled.
So boo to Nvidia for not just calling this what it is, but yay for doing it and giving users more options. I've never owned a 60Hz LCD monitor and I don't need to play games at 300fps, so it doesn't affect me much. I suppose it might be good for latency improvement in the games where I use Vsync and monitor backlight strobing.
michaelius
Banned
Are there any negatives when using it vs traditional vsync ?
How so? It's extremely worthwhile. Having a silly marketing name doesn't make having access to actual triple buffering again, finally, in all games, any less useful.
If your framerate is close to the refresh rate you could get worse framepacing.
AndyMoogle
Member
No.
EDIT: I should probably expand upon that. If you can get a game to run at 2-3 times your monitor's refresh rate then sure. So, in most cases this will be pointless for you.
ACH1LL3US
Member
Huh?
Anyway, people keep saying this is triple buffering, Tom clearly states it is not because of how the pipeline is handle, triple buffering causes backpressure, FAST sync does not! There is a large difference in input lag between FAST sync and triple buffering.
Smooth Operator
Member
FastSYNC could be great for fighting games on PC if it doesn't add input lag.
That's because for some reason he calls 3 buffer queues "triple buffering". They are not. Actual triple buffering, as described in many textbooks going all the way back to the 90s, is exactly what he describes as "fastsync".
Yes, he says this, but Tom is being disingenuous. It's perfectly possible to implement triple buffering and include logic to drop frames from one of the back buffers when it's not useful.
He is either taking the view that "triple buffering", as people understand it today, refers to DirectX's three-buffer-queue method, that does do as he describes and causes back pressure, or he is comparing to a more basic implementation of true triple buffering that cannot drop frames. Either way, Fast Sync is triple buffering. Please read the article I linked and in particular the Update section at the end.
Dictator93
Member
I think he is referring to the fact that you, confusing for some, have the same avatar as Dark10x (John of Digital Foundry).
dr_rus
Member
Probably because what he describes is what is actually implemented in all modern games as "triple buffering"?
Let's take the following 60Hz Monitor scenario:
Adaptive Vsync vs. FastSync in games like GTA maxed which from time to time can go under 60 (grass).
Yes, you can go grass medium/high, change a few opther options and stay above 60fps all time but for comparison's sake. Which one would be better?
Why does adaptive vsync not work that often and you get tearing? Is it engine dependant (frametimes)?
Adaptive Vsync vs. FastSync in games like GTA maxed which from time to time can go under 60 (grass).
Yes, you can go grass medium/high, change a few opther options and stay above 60fps all time but for comparison's sake. Which one would be better?
Why does adaptive vsync not work that often and you get tearing? Is it engine dependant (frametimes)?
Felix Lighter
Member
Adaptive vsync disables vsync when your framerate drops below your monitors refresh rate to prevent it from instantly dropping to 30 fps.
This is by design for adaptive. The point of it is to try to avoid controls latency. If using adaptive, vsync will disengage if your PC misses the display refresh interval, in your case, 16.7 ms and will re-engage when performance returns to that level or better.
Fast Sync (I'm going to hate writing that all the time), is not designed for the scenario you describe. It is to help controls latency when your frame rate is massively higher than your refresh rate. i.e. 60 Hz display and 300 fps.
SneakyStephan
Banned
No thanks, according to the explenation it makes the flow of time inconsistent ingame, which is incredibly distracting and offputting.
60 fps is not a reasonable treshold where that is no longer noticable, as nvidia themselves said it's for when you have 200+ fps
At which point tearing is no longer noticable anyhow
Niche halfbacked 'solution' for the tiny percentage of people who can still notice tearing at 200 fps (quite amazing as the offset from the tear will be very small) in the small percentage of games where you can get these kinds of framerates.
60 fps is not a reasonable treshold where that is no longer noticable, as nvidia themselves said it's for when you have 200+ fps
At which point tearing is no longer noticable anyhow
Niche halfbacked 'solution' for the tiny percentage of people who can still notice tearing at 200 fps (quite amazing as the offset from the tear will be very small) in the small percentage of games where you can get these kinds of framerates.
jediyoshi
Member
So what's your takeaway of the distinction between it and triple buffering?
The screen tear elimination aspect, but not the quick task switching. For nvidia on the driver level, you can already force triple buffering.
As I understand, the game will render as fast as possible, causing 100% GPU usage all time - 600 fps and up in some titles...
Wouldn't it be better to use this option in tandem with, say, RTSS capping at double the monitor refresh rate?
thanks to your friend, last years were crazy with so much syncs and dont have ideas about the differences.
The current feature in the Nvidia driver labelled Triple Buffering only applies to games that use an OpenGL renderer. Fast Sync is just triple buffering for DirectX games.
Why over 60fps though?
What do I do in the case in which I can't quite reach 60 fps or get frequent dips but still don't want tearing (the case for tripple buffering usually, or at least what people called tripple buffering in recent history)
Won't FastSynch help me with that as well?
Kaffeemann
Banned
Any information on when this will be available for Maxwell?
SmokedMeat
Gamer™
This sounds like something I've been needing for many of my older games.
This, it is getting annoying now.
AndyMoogle
Member
If you have a 60Hz monitor, then yes. If you have a 120/144 Hz monitor you would have to run the game at 240/288+ fps for it to be worthwhile.
ScepticMatt
Member
I'd like to see just-in-time v-sync, where the frame rendering is delayed to finish just before the next scanout. This should result in less input lag and lower power consumption compared to vsync, tripple buffered or not.
Valve experimented with it, but I never got it working smoothly. Maybe with the Vulkan update (hopefully) this week.
Valve experimented with it, but I never got it working smoothly. Maybe with the Vulkan update (hopefully) this week.
On a 60 Hz screen tearing is visible regardless of FPS. The tear line will be visible for 16.6 ms even at 5000 FPS.
I am confused....are you saying that with for example a 100Hz G-sync display, if I run a game and it drops from say, 100 frames all the way down to 30 frames or so, I will not notice a difference? Will it continue to look just as smooth, even at 30fps? Really? Because if so I'm getting a G-sync monitor.
AndyMoogle
Member
It's not going to look as smooth as 100 fps, obviously, but it's meant to get rid of the stutter that comes along with a variable framerate on a locked refresh rate. You will still notice a difference in smoothness because there are much fewer frames, but it's going to look a lot better than on a regular monitor.
There is no way to make it look as good as 100 fps, because you are seeing 100 unique frames of detail per second and 30 unique frames per second cannot compare. See above for an example. It's good tech, but there is no substitute for more frames. It would still be preferable to have 100 fps.
This is so much better than Gsync holy shit
I wouldn't use it for CS:GO but I would use it for every other game. Vsync forced off is a PC gaming staple for me.
Doesn't borderless window basically force vsync because of the shitty new Windows Aero you can't turn off?
I wouldn't use it for CS:GO but I would use it for every other game. Vsync forced off is a PC gaming staple for me.
Doesn't borderless window basically force vsync because of the shitty new Windows Aero you can't turn off?
AndyMoogle
Member
Better than GSYNC? Not even close. Fast Sync isn't worth using in most cases, while GSYNC/FreeSync is pretty much always worth it. You're saying that you'll use it for every other game than CSGO. You have to be able to run the game at 2-3x your monitor's refresh rate for it to be working well. It will be worse than Vsync for games you run at or around your monitor's refresh rate.
Using fastsync at a frame rate below your monitors refresh rate is functionally identical to using vsync, and you gain no latency advantage. Once your frame rate exceeds your monitors refresh rate you begin to see improvements in your latency. Once you exceed twice your monitors refresh rate (120 fps for 60 hz, 240 fps for 120hz, etc) you will see the full benefits of fastsync.
So basically this has 2 use cases:
1) Low to moderate frame rates and the user wants driver level triple buffering. They are willing to put up with judder and/or frame pacing issues. Latency improvement will be minimal or nonexistent over standard vsync.
2) Frame rates approaching or exceeding twice the refresh rate of the users monitor. The user will gain a latency improvement Nvidia claims is an average of only 8ms higher than running the game with vsync off.
I'm sure there is a middle ground between 1x the frame rate and 2x the frame rate where people will see a mixture of 1 and 2. I'd go even further and say that their 8ms claim exists only for gamers with a 144hz monitor. The advantage over vsync off on a 60hz display is likely to be far far less. Probably 20ms+ over vsync off.