XL2720 Input lag Leo bodnar Test

Adjusting BENQ Blur Reduction and DyAc (Dynamic Acceleration) including Blur Busters Strobe Utility. Supports most BenQ/Zowie Z-Series monitors (XL2411, XL2420, XL2720, XL2735, XL2540, XL2546)
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Angel Soler
Posts: 73
Joined: 14 Apr 2020, 17:49

XL2720 Input lag Leo bodnar Test

Post by Angel Soler » 02 Jun 2022, 02:28

Hello everyone.

I have opened a new thread as suggested by Chief.

The review of the XL2720 was on the Displaylag website (a website specialized in input lag. The reviewer is a professional Street Fighter player).

https://displaylag.com/benq-xl2720z-rev ... g-monitor/

The inputlag results are right out of the box.
I am not aware that the analyst has changed any parameter with the strobe utility or has changed anything in the vertical total setting.

Results with Led Bodnar and Blur Reduction activated :

Top: 6.7ms
Middle: 15.0ms
Bottom: 23.3ms

I have the following doubts:

1) If the Ledo Bodnar measures input lag at 60hz with v-sync on, why is there a different input lag in each part of the screen?...shouldn't it be the same input lag in the whole screen?

2) can these results be extrapolated to the XL2411P?


My biggest concern, and the reason for all these questions, is that I need to know the input lag of the Viewsonic XG2431 at 60hz with v-sync activated (exclusive gaming console)

Now I have the XL2411P, and I'm happy with the input lag. I am a very competitive player and I have very good results.

And since the Benq XL2411P and the Viewsonic XG2431 I think are very similar in certain things, I wanted to know if they can be comparable in input lag.

If the input lag of the XG2431 is equal to or less than the XL2411P I would be very happy and I would buy it without thinking about it.


Chief, I don't want to bother you anymore with so many questions. You are very kind and I do not want to abuse your kindness.

So the only real question and concern is:

If I buy the XG2431, will I have input lag as low as the Xl2411P? and if it is lower then even better :)

It would be great, because the XG2431's strobe mode at 60hz is fantastic.
It would be a dream, and it would really be an experience as good as a CRT :)
Recuerda que siempre jugaré con consola: 60 hz y V-Sync ON


Thank you very much for your time and for your interest in helping me.

I really don't want to bother you anymore.

I have learned a lot from you and you are the only person who can really help me :)

Discovering this forum has been fantastic.

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Discorz
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Re: XL2720 Input lag Leo bodnar Test

Post by Discorz » 02 Jun 2022, 14:32

Try Aperture Grille's Latecy Split Test to get a sense of how much is 1, 5, 10... ms of lag. I wouldn't worry to much about it. Although Im not familiar with those old 2013/14 zowie monitors. Maybe lateny was higher back than.
Last edited by Discorz on 02 Jun 2022, 16:00, edited 1 time in total.
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Chief Blur Buster
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Re: XL2720 Input lag Leo bodnar Test

Post by Chief Blur Buster » 02 Jun 2022, 16:00

Angel Soler wrote:
02 Jun 2022, 02:28
https://displaylag.com/benq-xl2720z-rev ... g-monitor/

The inputlag results are right out of the box.
I am not aware that the analyst has changed any parameter with the strobe utility or has changed anything in the vertical total setting.

Results with Led Bodnar and Blur Reduction activated :

Top: 6.7ms
Middle: 15.0ms
Bottom: 23.3ms

I have the following doubts:

1) If the Ledo Bodnar measures input lag at 60hz with v-sync on, why is there a different input lag in each part of the screen?...shouldn't it be the same input lag in the whole screen?
This is only true if strobe crosstalk is successfully zeroed out.

But since that is not done, you have the early double-image at top with the current refresh cycle. And the late double-image at bottom with the current refresh cycle.

Also Leo Bodnar is a black box with only approximate assumed latency stopwatching thresholds, it may be keying on the strobe crosstalk.

From a pure mathematical standpoint, zero-crosstalk strobing would have equalized latency for all pixels during VSYNC ON. However, strobe crosstalk is very bad at the top and bottom 20% of the screen, where there Leo Bodnar squares are flashing, and this will create offsets to LCD GtG%-based latency stopwatching-stop trigger points. You might see a situation where only the middle 60%-75% crosstalkless area of the screen is latency-equallized, while the edges of the screen has crosstalk.

Also, ultra-sensitive GtG stopwatching thresholds (e.g. 1%) may stopwatch far before human-detection thresholds, and thus latency numbers from equipment may be synthetic relative to human-vision thresholds.

Image

Even GtG1% and GtG3% is human visible, even though VESA measures only 10%-to-90% to accommodate the noisefloors of various different oscilloscope equipment.

Many lag testers have different GtG% stopwatch triggers, sometimes it's closer to GtG2% and other times it's closer to GtG100%. I tend to prefer human-vision-perception-based GtG% triggers like GtG10% or GtG50% for stopping the latency stopwatch, but I will settle for better latency stopwatching disclosure from websites.
Angel Soler wrote:
02 Jun 2022, 02:28
2) can these results be extrapolated to the XL2411P?
Not necessarily. That being said, the monitor models are extremely similar with both similar 60Hz single strobe support, and might be extrapolatable. However, crosstalk varies hugely on different panels.

The problem is that you might have GtG8% on one monitor for the strobe crosstalk double image and GtG12% on a second monitor for the same crosstalk double image. Both are human visible. But a lag tester keyed to stopwatch-stop on GtG10% will have 1 frame less lag for the top edge.

The middle number is the most extrapolatable. One monitor would have the middle number for 70% of the panel height, and a different monitor might have the same middle number but for 60% or 80% of the panel height, assuming the GtG% stopwatch-stop trigger was not modified.

Also, some strobe backlights are semi-scanning based. The Samsung CHG70 series has the defacto equivalent of a 4-segment scanning backlight that pulses from top to bottom. This would create lag numbers closer to non-strobed than strobed.

Also Leo Bodnar, has some undiagnosed weirdnesses with strobed displays, triggering differently on GtG% when strobed than when nonstrobed. Since it's such a black box (literally) it's hard to determine how it lag-stopwatches.

Strobe crosstalk is not linear along the vertical dimension of the screen so you may see a sudden click-to-middle behavior when you move the sensor slightly further down (if a specific lag tester has adjustable-position squares, like between TOP and TOP-MIDDLE).
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Angel Soler
Posts: 73
Joined: 14 Apr 2020, 17:49

Re: XL2720 Input lag Leo bodnar Test

Post by Angel Soler » 03 Jun 2022, 02:53

Chief Blur Buster wrote:
02 Jun 2022, 16:00
Angel Soler wrote:
02 Jun 2022, 02:28
https://displaylag.com/benq-xl2720z-rev ... g-monitor/

The inputlag results are right out of the box.
I am not aware that the analyst has changed any parameter with the strobe utility or has changed anything in the vertical total setting.

Results with Led Bodnar and Blur Reduction activated :

Top: 6.7ms
Middle: 15.0ms
Bottom: 23.3ms

I have the following doubts:

1) If the Ledo Bodnar measures input lag at 60hz with v-sync on, why is there a different input lag in each part of the screen?...shouldn't it be the same input lag in the whole screen?
This is only true if strobe crosstalk is successfully zeroed out.

But since that is not done, you have the early double-image at top with the current refresh cycle. And the late double-image at bottom with the current refresh cycle.

Also Leo Bodnar is a black box with only approximate assumed latency stopwatching thresholds, it may be keying on the strobe crosstalk.

From a pure mathematical standpoint, zero-crosstalk strobing would have equalized latency for all pixels during VSYNC ON. However, strobe crosstalk is very bad at the top and bottom 20% of the screen, where there Leo Bodnar squares are flashing, and this will create offsets to LCD GtG%-based latency stopwatching-stop trigger points. You might see a situation where only the middle 60%-75% crosstalkless area of the screen is latency-equallized, while the edges of the screen has crosstalk.

Also, ultra-sensitive GtG stopwatching thresholds (e.g. 1%) may stopwatch far before human-detection thresholds, and thus latency numbers from equipment may be synthetic relative to human-vision thresholds.

Image

Even GtG1% and GtG3% is human visible, even though VESA measures only 10%-to-90% to accommodate the noisefloors of various different oscilloscope equipment.

Many lag testers have different GtG% stopwatch triggers, sometimes it's closer to GtG2% and other times it's closer to GtG100%. I tend to prefer human-vision-perception-based GtG% triggers like GtG10% or GtG50% for stopping the latency stopwatch, but I will settle for better latency stopwatching disclosure from websites.
Angel Soler wrote:
02 Jun 2022, 02:28
2) can these results be extrapolated to the XL2411P?
Not necessarily. That being said, the monitor models are extremely similar with both similar 60Hz single strobe support, and might be extrapolatable. However, crosstalk varies hugely on different panels.

The problem is that you might have GtG8% on one monitor for the strobe crosstalk double image and GtG12% on a second monitor for the same crosstalk double image. Both are human visible. But a lag tester keyed to stopwatch-stop on GtG10% will have 1 frame less lag for the top edge.

The middle number is the most extrapolatable. One monitor would have the middle number for 70% of the panel height, and a different monitor might have the same middle number but for 60% or 80% of the panel height, assuming the GtG% stopwatch-stop trigger was not modified.

Also, some strobe backlights are semi-scanning based. The Samsung CHG70 series has the defacto equivalent of a 4-segment scanning backlight that pulses from top to bottom. This would create lag numbers closer to non-strobed than strobed.

Also Leo Bodnar, has some undiagnosed weirdnesses with strobed displays, triggering differently on GtG% when strobed than when nonstrobed. Since it's such a black box (literally) it's hard to determine how it lag-stopwatches.

Strobe crosstalk is not linear along the vertical dimension of the screen so you may see a sudden click-to-middle behavior when you move the sensor slightly further down (if a specific lag tester has adjustable-position squares, like between TOP and TOP-MIDDLE).
Thank you very much for such a complete answer.:)

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