Understanding the implications of ULMB2 on the PG27AQN

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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hanimikhail
Posts: 2
Joined: 31 May 2023, 21:23

Understanding the implications of ULMB2 on the PG27AQN

Post by hanimikhail » 31 May 2023, 21:57

Hi all,

Just recently updated my monitor and have been trying to understand the science behind blur reduction. Based on previous explanations on this forum I have a few questions:

1. Should I be reducing my frame rate and refresh rate to 220, based on the average GtG of this panel?

- Average GtG with overdrive on normal is 1.5ms
(as reported at 3:50 https://youtu.be/xDTWG_3edpo by OptimumTech)
- Assume ULMB2 pulse width 10% = 0.25ms strobe
- 1/360 = 2.77ms

Therefore:
Perfect strobe interval = Max refresh + GtG + MPRT
2.8 + 1.5 + 0.25 = 4.55ms
1000/4.55 = 219.8 FPS

Does this mean I need to reduce monitor refresh rate to 240 and capping FPS at 240 to eliminate strobe cross perfectly? What then is the effective motion clarity? Is it just based on the MPRT? So 4000hz? Or is it less than running at 360fps 360hz?

2. By having an MPRT that exceeds GtG, and therefore uncoupling motion blur from refresh rate, does this also imply that running an FPS much higher than Hz perceptually increases the response time of the monitor to the FPS?

I play mainly OW2 which I can run with perfect frame times at 540fps after endless optimisations. I also use a 8khz 7200dpi DAV3 for mouse input. Given that the render que will only ever send the most recent frames to my monitor, my GPU to monitor latency will be 1.85ms for any given frame, but the transition between frames will still be a 2.77ms interval.

Strobing tricks the brain into interpolating this transition down to 0.25ms. But because it can’t predict the future, my latency remains at 1.85ms. However, my brain is no longer dependant on the refresh rate for data, but now the FPS. Although I still only see 2.77ms frames, they are generated at 1.85ms - and since my brain is filling in the interval with strobing - I theoretically bypass the hz of the monitor and my brain interpolates movement at 540fps latency. This seems to make sense to me, can anyone correct me?

3. Acknowledging the problems with halos and reduced brightness, if my brain doesn’t have a problem with 0.25ms strobing, are there any actual disadvantages compared to having a strobeless 4000hz display?

And extending on from this, if >10,000hz is where the stroboscopic effect disappears and we become unable to distinguish screen motion from reality, isn’t it much more likely that LCDs with sophisticated very bright local dimming and MRPTs of 0.1ms will be made before an OLED with strobeless 4000hz.

tombox
Posts: 15
Joined: 05 Aug 2019, 02:56

Re: Understanding the implications of ULMB2 on the PG27AQN

Post by tombox » 01 Jun 2023, 06:32

While you're waiting for an answer, how do you like your monitor for OW2? Is the jump from 240hz to 360hz with ulmb 2 a big upgrade? I'm on the fence between this/acer 360hz ips ulmb 2 monitor and an oled.

hanimikhail
Posts: 2
Joined: 31 May 2023, 21:23

Re: Understanding the implications of ULMB2 on the PG27AQN

Post by hanimikhail » 01 Jun 2023, 07:18

tombox wrote:
01 Jun 2023, 06:32
While you're waiting for an answer, how do you like your monitor for OW2? Is the jump from 240hz to 360hz with ulmb 2 a big upgrade? I'm on the fence between this/acer 360hz ips ulmb 2 monitor and an oled.
TLDR; if you want the smoothest experience PG27AQN all the way, otherwise consider the 45inch OLEDs - they're awesome.

Yeah, so I've also got the newly released 45GR95QE-B from LG (3440x1440 240hz 45inch OLED) and I do love it. The size is incredible for gaming, I find it considerably easier to aim and the curvature is sorely missed when moving back to the PG27AQN. OLED is fantastic for the contrast and colour quality.

All of that being said, I do notice the difference between 240hz and 360hz - I know some people say it is negligible, but what I think they actually mean is that you can get used to 240hz quickly. Every time I switch back I notice the reduced latency and smoothness. However, motion clarity was comparable. Once my brain adjusted to the 240hz interval - I didn't find movement jarring on the OLED.

With ULMB 2 it really just feels like the PG27AQN got DyAc+. And that's with the pulse width on 100. I've since left it on 10, and closed the blinds in my room. I have no idea what the MRPT is at that level, but I've assumed it's close to 0.25ms. And the only way to describe it is the same way people feel when going from 144 --> 240 or 240 --> 360. It's subtle and unnerving.

So ultimately I find both have their beauty for OW2. If I had just gotten the 27inch OLED I would probably urge you to just get the PG27AQN, because the only real benefit there is contrast and colours. My dream monitor would be what LG are likely to output next - which is a 1440p ultrawide 480hz OLED 45inch display with some capacity for strobing. Otherwise, I think Nvidia have convinced me that LCD will remain the best option until we can get 1000hz+ strobless. Perhaps ULMB 2 will push monitors toward LCD with better local dimming zones?

bumbeen
Posts: 84
Joined: 25 Apr 2023, 14:35

Re: Understanding the implications of ULMB2 on the PG27AQN

Post by bumbeen » 06 Jun 2023, 03:08

it does look cleaner at lower refresh rates yeah. By the way, you don't have to turn off g-sync globally and you can make it turn on ULMB per game, but you cannot use the ULMB option in nv control panel. You set the game specific setting to "Fixed Refresh". Once you launch the game, then you can turn ULMB on with the OSD. Thereafter, it will switch between ULMB and G-sync on its own.

Umarrii
Posts: 1
Joined: 29 Jul 2023, 20:24

Re: Understanding the implications of ULMB2 on the PG27AQN

Post by Umarrii » 29 Jul 2023, 20:28

Was wondering if anyone has a complete guide on settings to use with ULMB2 for Overwatch 2? Would be very interested! 😯

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