ULMB and fast sync

Ask about motion blur reduction in gaming monitors. Includes ULMB (Ultra Low Motion Blur), NVIDIA LightBoost, ASUS ELMB, BenQ/Zowie DyAc, Turbo240, ToastyX Strobelight, etc.
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kandor1978
Posts: 53
Joined: 09 Aug 2016, 20:02

ULMB and fast sync

Post by kandor1978 » 12 Dec 2016, 21:36

Hi everyone,

I have found something quiet interesting I think
When running vsync on in ULMB mode we have the regular frame halving when a certain fps is reached which makes things really bad in my opinion

Without vsync there is tearing which also makes things bad (again my opinion)

So I tried fast sync
This mode is kind of a mess to be honest because it stutters alot and sometimes freezes the game even for a second

I have found this quiet interesting, you can run the games at any fps you like with a fps limiter and there is no tearing, for example, I tried from 70fps to 89fps on my 120hz ulmb mode and there was no halving to 60 like normal vsync

So I tried to set the fps limiter to 120fps and it actually runs all games I tried alot better than when no fps limiting
For example CSGO would run to its max 240fps and would stutter alot
Limited to 120 and its pretty doable to be honest
Its not gsync fluidity but not too bad anyway

Also found with battlefield hardline you need to add a line to your user.cfg or it would freeze lag every few seconds
This was not needed for battlefield 1 though

this was the line (I dont know to be honest what it does but it works)
RenderDevice.PresentAsync 0

Anyway if anyone is up for testing this and tell their opinion compared to regular vsync in ULMB mode and give their opinion

Best,
Kandor

Sparky
Posts: 682
Joined: 15 Jan 2014, 02:29

Re: ULMB and fast sync

Post by Sparky » 12 Dec 2016, 21:58

The tradeoff between v-sync and fast sync is latency vs smoothness, and there's only a difference between them if your framerate exceeds your refresh rate.
this was the line (I dont know to be honest what it does but it works)
RenderDevice.PresentAsync 0
That sounds like just another name for vanilla v sync, which adds a lot of latency. Could also be a synchronous framerate cap, which would be a very good thing.

kandor1978
Posts: 53
Joined: 09 Aug 2016, 20:02

Re: ULMB and fast sync

Post by kandor1978 » 13 Dec 2016, 04:57

Sparky wrote:The tradeoff between v-sync and fast sync is latency vs smoothness, and there's only a difference between them if your framerate exceeds your refresh rate.
this was the line (I dont know to be honest what it does but it works)
RenderDevice.PresentAsync 0
That sounds like just another name for vanilla v sync, which adds a lot of latency. Could also be a synchronous framerate cap, which would be a very good thing.

I don't agree that its like vanilla vsync because I can run it at any fps without it limiting to something that is devidable with 120.
I could run at 70-89 that I tried

Also the latency is lower, I can feel the difference with vsync hitting 120 fps compared to this

Best,
Kandor

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RealNC
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Re: ULMB and fast sync

Post by RealNC » 13 Dec 2016, 07:44

Fastsync with FPS=Hz is pretty much like vsync with frame cap = Hz. You don't win much, but you still get some microstutter.

Have you tried using CRU to change your refresh rates to X.006 or so? For example, 120.006Hz with a 120Hz cap and vsync on should give you very good latency.

By default, most monitors don't use exactly 120Hz. They're a bit lower (like 119.982Hz). Capping to 120FPS with vsync on doesn't help as much in this case.

I recommend using CRU to change the refresh rate to 120.006 (or whatever the closest is to that), use vsync and cap FPS to 120. This should give you low input lag without the microstutter of fastsync.
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kandor1978
Posts: 53
Joined: 09 Aug 2016, 20:02

Re: ULMB and fast sync

Post by kandor1978 » 13 Dec 2016, 09:30

RealNC wrote:Fastsync with FPS=Hz is pretty much like vsync with frame cap = Hz. You don't win much, but you still get some microstutter.

Have you tried using CRU to change your refresh rates to X.006 or so? For example, 120.006Hz with a 120Hz cap and vsync on should give you very good latency.

By default, most monitors don't use exactly 120Hz. They're a bit lower (like 119.982Hz). Capping to 120FPS with vsync on doesn't help as much in this case.

I recommend using CRU to change the refresh rate to 120.006 (or whatever the closest is to that), use vsync and cap FPS to 120. This should give you low input lag without the microstutter of fastsync.


I try that

But normal vsync has another issue which is that its not free on how many fps each refresh can run
For example
When it drops to say 100 for a moment it will go down from 120fps to locked 60fps for a little while
and then jump up to 120

With this method I noticed the fps is totally free. it can be at any fps and it wont lock anything
and there is no tearing thanks to fast sync

The microstutter is there unfortunatley. but not much more than vsync off to be honest. only way I can get it alot smoother is running everything in gsync mode

Anyway will try the cru option and see how that goes

Best,
Kandor

kandor1978
Posts: 53
Joined: 09 Aug 2016, 20:02

Re: ULMB and fast sync

Post by kandor1978 » 13 Dec 2016, 14:32

I have now tried vsync on and limiter with a fraction lower fps than screen hz and it indeed is very smooth if you can keep up with the fps needed

I find even going 2fps lower than screen hz makes it stutter too much to my liking
Damn I wish there was gsync and strobing sametime. not the hacked kind

Best,
Kandor

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