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Does G-SYNC reduce motion blur?

Posted: 12 May 2014, 06:21
by whitestar
I realise this may be a silly question, but I seem to have missed whether G-SYNC itself will reduce motion blur. Will it?

For example, if I play with G-SYNC on and the speed is 60fps@60hz, will that give less motion blur than say on my current Benq XL2411T at 60fps@60hz (without LightBoost)?

I read this: "Based on BenQ's market-changing XL gaming monitor series, the new XL2420G and XL2720G displays add three new G-Sync gaming modes to further augment the gaming experience: the G-Sync Mode for smooth, low-latency gaming; Low Motion Blur Mode for CRT-like sharpness of moving objects; and a full-featured 3D Vision Mode to create more lifelike on-screen action."

I'm confused. I thought you had to choose between low motion blur and G-SYNC, but the way they write it you'd think G-SYNC was present along with low motion blur: "three new G-Sync gaming modes".

Re: Does G-SYNC reduce motion blur?

Posted: 12 May 2014, 07:27
by RealNC
G-Sync doesn't reduce motion blur.

Yes, the wording is somewhat misleading. But that's how marketing works in general; they're trying to make things look better than they actually are :-)

There are no monitors at this time, nor have any been announced, that would allow you to use G-Sync and backlight strobing at the same time.

Re: Does G-SYNC reduce motion blur?

Posted: 12 May 2014, 08:11
by whitestar
Ok, thanks for a very clear answer. Then it is as I feared unfortunately. :)

Does this mean that the motion blur varies along with the variation in fps/hz when you play on a G-Sync monitor? Or doesn't it work like that?

I mean, on my Benq now I play Far Cry 3 at 85hz (vsync on), because there is notably less motion blur at 85 compared to 60. And I am able to keep 85fps+ like 99% of the time.

But let's say that on a G-Sync monitor, if the fps drops to 60 in some game, then will the monitor hz drop to 60 as well and therefore the motion blur increase? Or maybe I'm just misunderstanding the whole deal with G-Sync. :)

Re: Does G-SYNC reduce motion blur?

Posted: 12 May 2014, 09:32
by RealNC
whitestar wrote:But let's say that on a G-Sync monitor, if the fps drops to 60 in some game, then will the monitor hz drop to 60 as well and therefore the motion blur increase?
Yes, that's correct. You will get as much or as little motion blur as your monitor produces at the specific refresh rate that G-Sync is currently using. If your games usually run at high frame rates, and only drop down to 60 or 50 for very short periods of time (like 1 second or so), then you're not really going to notice this. G-Sync in this case acts as a stutter-prevention method (I hear that Battlefield 4 does that a lot, which is why G-Sync helps so much in keeping this game appear more fluid.)

For games where you simply cannot maintain a high frame rate, then you need to decide what the lesser evil is for you. Stutter, or some extra motion blur? Stutter imo is way more annoying.

Re: Does G-SYNC reduce motion blur?

Posted: 12 May 2014, 11:56
by Chief Blur Buster
RealNC wrote:For games where you simply cannot maintain a high frame rate, then you need to decide what the lesser evil is for you. Stutter, or some extra motion blur? Stutter imo is way more annoying.
For low frame rates, GSYNC really does a superb job on that. You really want to enable GSYNC for games like BF4 or Crysis3, since the framerates fly all over the place. The only way wildly varying framerates can become stutterfree is wildly varying refresh rate perfectly in sync - aka GSYNC. 40fps thru 70fps randomized looks like one big smooth framerate, as if 60fps@60Hz perfect sync. In that sense, GSYNC is miraculous in undoing stutter visibility of that.

However...
The moment I can sustain darn near perfect 85fps at 85Hz (VSYNC ON and solo gaming when a bit of lag doesnt matter), I prefer the simultaneously blurfree / tearfree / stutterfree experience of blur reduction modes (LightBoost sequels that doesn't affect color much, such as ULMB, Turbo240 or BENQ Blure Reduction)

Re: Does G-SYNC reduce motion blur?

Posted: 12 May 2014, 17:23
by whitestar
What about 75fps@75hz? Are those LightBoost sequels also attainable at that speed?

I can see myself using G-Sync on Skyrim and maybe Crysis 1/3. And maybe ULMB on Far Cry 3, if possible at 75/75.

Re: Does G-SYNC reduce motion blur?

Posted: 14 May 2014, 03:36
by Edmond
We are supposed to get a 4096x2160 30" oled monitor this year. I wonder if that is a low persistance oled just like oculusDK2.

If they make a gsync version then you get all the wonderful cleaned up framerate with gsync and about 2ms pixel persistance regardless of framerate.

Sorry for slightly off topic. But i wanted say that a low motion blur + gsync gameplay can only be possible with an OLED. Until then we have to choose. Feel free to correct me.

Re: Does G-SYNC reduce motion blur?

Posted: 14 May 2014, 03:46
by Chief Blur Buster
Edmond wrote:If they make a gsync version then you get all the wonderful cleaned up framerate with gsync and about 2ms pixel persistance regardless of framerate.
Not necessarily.
OLED is sample-and-hold, and has lots of motion blur -- Why Do Some OLEDs Have Motion Blur?. There's been several discussions elsewhere about the large amount of motion blur that still remains on flickerfree OLEDs -- Outlook for Blur Reduction in OLED (or the lack thereof), but fortunately, the OLED manufacturers are working to solve this problem.

You need to strobe an OLED too, in order to achieve low persistence.
Oculus Development Kit 2 uses strobing to achieve low persistence.

Re: Does G-SYNC reduce motion blur?

Posted: 14 May 2014, 04:38
by Edmond
Chief Blur Buster wrote:
Edmond wrote:If they make a gsync version then you get all the wonderful cleaned up framerate with gsync and about 2ms pixel persistance regardless of framerate.
Not necessarily.
OLED is sample-and-hold, and has lots of motion blur -- Why Do Some OLEDs Have Motion Blur?. There's been several discussions elsewhere about the large amount of motion blur that still remains on flickerfree OLEDs -- Outlook for Blur Reduction in OLED (or the lack thereof), but fortunately, the OLED manufacturers are working to solve this problem.

You need to strobe an OLED too, in order to achieve low persistence.
Oculus Development Kit 2 uses strobing to achieve low persistence.
Fuck me sideways. Are you telling me the only way with existing tech to get a flicker free low persistance gameplay is to have 500fps@500hz?

WELL, i hear oleds are capable of high refreshes like 500hz.
250fps@250hz for the 4ms persistance seems enough and even possible in my lifetime, i would argue that the additional 2ms costs way too much gpu power and monitor bandwidth to be realistic for the masses.

EDIT:
Gsync would certainly be a must on a 250hz monitor tho, cuz there is no way anyone is going to hold constant 250fps. Also something like that would bring an era where upgrading your video card not only makes things smoother but also reduces motion blur. Actually... it seems this is the case with gsync. The more framerate you have the more smoothness and less blur you have(current cap 6.9ms persistance @144hz).

Re: Does G-SYNC reduce motion blur?

Posted: 14 May 2014, 04:51
by Chief Blur Buster
Edmond wrote:
Chief Blur Buster wrote:
Edmond wrote:If they make a gsync version then you get all the wonderful cleaned up framerate with gsync and about 2ms pixel persistance regardless of framerate.
Not necessarily.
OLED is sample-and-hold, and has lots of motion blur -- Why Do Some OLEDs Have Motion Blur?. There's been several discussions elsewhere about the large amount of motion blur that still remains on flickerfree OLEDs -- Outlook for Blur Reduction in OLED (or the lack thereof), but fortunately, the OLED manufacturers are working to solve this problem.

You need to strobe an OLED too, in order to achieve low persistence.
Oculus Development Kit 2 uses strobing to achieve low persistence.
Fuck me sideways. Are you telling me the only way with existing tech to get a flicker free low persistance gameplay is to have 500fps@500hz?
Essentially, yes, if you hate any form of strobing -- pick your poison; some form of flicker/strobing/light modulation or motion blur.
Mathematically, persistence of any flickerfree display technology the full refresh cycle, or (1/Hz)th of a second. So a 120Hz flickerfree display (OLED, LCD, whatever) always has a guaranteed minimum of 1/120sec = 8.3ms persistence.

That's also why 240Hz HDTV's use interpolation to achieve lower persistence without unacceptable flicker.
Right now, strobed 120Hz monitors have less motion blur than most OLEDs in their default mode. OLEDs have very fast GtG transitions and are very strobe-friendly.

Good educational animations include:
Persistence-based motion blur: www.testufo.com/eyetracking
Strobing to reduce motion blur: www.testufo.com/blackframes
Relationship between persistence and blur (black frame duty cycle): www.testufo.com/blackframes#count=3
Edmond wrote:WELL, i hear oleds are capable of high refreshes like 500hz. (250fps@250hz for the 4ms persistance seems enough and even possible in my lifetime, i would argue that the additional 2ms costs way too much gpu power and monitor bandwidth to be realistic for the masses)
One could have 240Hz strobed at 1ms each. 240Hz flicker is not noticeable to most people, especially since motion-blur-reduction strobing typically has less eyestrain (on average) than PWM dimming, due to the lack of uncomfortable PWM motion artifacts. In fact, the LightBoost FAQ has entries for both "Why Does LightBoost Have MORE Eyestrain?" and "Why Does LightBoost Have LESS Eyestrain?" since dozens of people have reported in either direction (e.g. people who never got CRT eyestrain but gets PWM-dimming eyestrain).

240Hz has already been done before; they are in HDTVs but use interpolation. And cirthix has already hacked a 120Hz LCD to do true 240Hz. It's only a matter of time (probably less than 3 years) that the first native-240Hz gaming monitor would probably hit the market. One question I have, is whether at 240Hz, the LCD GtG transitions are fast enough to occur between refreshes, to allow strobing to be feasible without hugely noticeable strobe crosstalk. Best done in a fast-transition display such as an OLED panel, however.