Is Flicker Free with ULMB or LightBoost possible?

[Irlwizard]

From what I understand Flicker Free as BenQ call is a monitor with hardware that does NOT USE 'PWM' Pulse Free Modulation. A monitor with PWM (bad monitor for the eyes) has its brightness level controlled by the amount of times the backlight is turned on/off so at 50% brightness with a PWM monitor, your screen would be turning on and off at max brightness to give the illusion that it is not so bright. This causes 'flicker' and is damaging to the eyes. A NON-PWM monitor will adjust the brightness based on the voltage going to the monitor instead, e.g. if 12V gives a monitor 100% brightness, when you set the NON-PWM monitor to 50% it will only give 6V to the monitor, so the backlight is lit at constant lighting, this reduces the strains on your eyes. Is that correct?

If so, I am on the hunt for a 24" flicker free monitor with low ghosting and high frame rates and keep seeing the term 'strobed' what is that? No one ever gives a little definition of it and assumes everyone understand what STROBED refers to.

Anyway the monitor I want HAS to be flicker free in all modes, gaming/movie/reading/all-the-time! But have a sharp picture with low input lag, low to no ghosting and high frame rates with accurate color calibration.

So here are the main questions.
Q1: What is Strobed?
Q2: Is ULBM 'flicker free'?
Q3: Is LightBoost 'flicker free'?
Q4: Is G-Sync 'flicker free'? (not interested in FreeSync, too much ghosting).
Q5: Is BenQ blur reduction 'flicker free'?
Q6: Is BenQ blur reduction a TYPE of ULBM or LightBoost?
Q7: Does BenQ blur reduction STACK with ULBM or LightBoost? If so, do ALL OEM blur reduction things also stack with ULBM or LightBoost (I'm sure Asus/Acer or AOC have their own 'BenQ blur reduction' tech).

You don't have to answer all the questions in one go - if you only know the answer to one or two, please share it.

[masterotaku]

Q1: What is Strobed?
Q2: Is ULBM 'flicker free'?
Q3: Is LightBoost 'flicker free'?
Q4: Is G-Sync 'flicker free'? (not interested in FreeSync, too much ghosting).
Q5: Is BenQ blur reduction 'flicker free'?
Q6: Is BenQ blur reduction a TYPE of ULBM or LightBoost?
Q7: Does BenQ blur reduction STACK with ULBM or LightBoost? If so, do ALL OEM blur reduction things also stack with ULBM or LightBoost (I'm sure Asus/Acer or AOC have their own 'BenQ blur reduction' tech).

A1: The screen flashes once per Hz. The monitor spends most of the time with the backlight off. It flickers, but most people don't notice it at around 75Hz and above. The main advantage is little to zero motion blur, depending on how long is the strobing.
A2: No, because it's a strobing mode. It's better than Lighboost because it works at 85, 100 and 120 Hz in most G-Sync monitors.
A3: Same answer as before.
A4: Yes. It doesn't use strobing and it also doesn't have PWM.
A5: BenQ Blur Reduction is also a strobing technique, like ULMB and Lighboost. It can be enabled from 50Hz to 144Hz (or a bit more if you have success overclocking your monitor. I reached 146Hz).
A6: It's different, and not owned by Nvidia. You can use it with any GPU, and even with consoles.
A7: No to all those questions. You use one or the other, or nothing at all. For example, in the BenQs the service menu (where you can configure blur reduction) doesn't affect anything while you are using Lighboost.

Edit: I had answers 2 and 3 reversed.

[Falkentyne]

Asus and Acer do NOT have their own blur reduction tech. They just use Nvidia's Gsync/ULMB
ULMB is done by Nvidia hardware (it's more or less the sequel to lightboost) and can only be used on Gsync monitors AND with Nvidia video cards, even though it's monitor based, it's vendor locked. Lightboost was more or less a 'hack', because that was supposed to be used with 3d vision goggles, but we found out that it can be left on and used on the desktop.

The only companies that have their own blur reduction tech that are NOT vendor locked are Sony (for TV's), Benq (MBR), Eizo (motion 240) and LG (turbo 240).
LG's turbo240 can only be used at 120hz and their input lag reduction thing (DCS? DCR? I forgot...check tom's hardware review) can't be used with turbo240 enabled, making the input lag higher than the other systems. Benq MBR doesn't suffer from this and is the most tweakable, as Masterotaku said. Eizo's motion 240 is limited, also.
Samsung had a strobing backlight on a few of their monitors for AMD cards but I forgot what it's called, and I remember the ghosting or input lag was pretty unbearable.

[Irlwizard]

First of all thank you masterotaku and Falkentyne for giving detailed and educational answers, they help me understand monitor reviews and I am sure they will help a lot of other people that read this topic.

A6: It's different, and not owned by Nvidia. You can use it with any GPU, and even with consoles.

Does this mean that BenQ Blur Reducton can be used together with G-Sync? I know that you can't enable ULMB and G-Sync at the same time. I am guessing the answer will be no because BenQ Blur Reduction seems to run on BenQs own monitor hardware chip.

A7: No to all those questions. You use one or the other, or nothing at all. For example, in the BenQs the service menu (where you can configure blur reduction) doesn't affect anything while you are using Lighboost.

So which one is better ULMB or BenQ Blur Reduction, if you have the option of choosing, like on the new BenQ Hybrid monitor.
Are you able go give an order or point out pros/cons? e.g. ULMB > Lightboost > BenQ Blur Reduction.


As far as eye care goes. A PWM monitor on 100% brightness does not cause (invisible) flashing by turning itself on and off. But it seems that ALL 'strobing' tech/modes DOES! That makes me wonder... If we assume that flicker is bad for the eyes - isn't strobing worse for the eyes then PWM, because even at 100% brightness level during strobing mode the monitor still flashes to black. So what is even the point of buying a non-PWM monitor if you plan to use strobing tech for say FPS games? Because you have to set the brightness to 100% during strobing anyway as you only get seem to get a 60-65% brightness drop during these modes according to reviews (meaning that on 100% brightness with strobing you are basically not benefiting from the non-PWM feature at all).

[Falkentyne]

Gsync and benq blur reduction are mutually exclusive.
Gsync can only be used in MONITORS equipped with Gsync scalers. Benq blur reduction based monitors do not use a gsync scaler. So the benq blur reduction monitors are not gsync compatible. And strobed backlights can not be used with freesync (AMD's version of gsync, to keep things simple) either. Even the XL2420G, which has a gsync scaler, can not be used at the same time as the blur reduction module, because the blur reduction module is on a completely different scaler (the Mstar 8556T, I think). there's a hardware switch on the back of the screen that lets you switch between the two scaler circuits/chips.

Gsync scalers have ULMB as their motion blur tech, and that can only be used with Nvidia hardware.

Which one is better?
Benq blur reduction, IMO. BBR can be used at 60 to 144 hz refresh rates, in 1 hz increments, while Gsync (ULMB) is limited to 85, 100 and 120hz (120hz on the ROG swift).

And as far as what's worse' for the eyes, well...a strobed backlight is no worse than a CRT. And we used CRT for years, so...
Just looking at a LCD's backlight for hours on end can be bad for the eyes, strobed or not. What matters is if you get headaches or dizzy from it. Some people can handle 60hz CRT flicker. Some can't handle PWM at all (I never once noticed the PWM on my VG248QE at all, while some people complained of getting sick from the PWM on it).