BenQ XL2411P scrolling horizontal lines

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TheOneAndOnlyJP
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BenQ XL2411P scrolling horizontal lines

Post by TheOneAndOnlyJP » 08 May 2018, 22:14

When turning instant mode on and off the speed and intensity of these strange down-scrolling lines changes. I noticed it when turning instant mode off and they were very slow scrolling and apparent, but when I turned the setting on and off again the lines are more faint and scroll down faster; they look like this:

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If I gently roll my eyes downward on the screen I can see them faintly come down quick.


Here's a great example, except the lines moving in the opposite direction:

https://youtu.be/2UyxRepRg54


An update on the situation: A few minutes ago I noticed the lines are faint and fast moving at 144hz, but at 120hz the lines are slower and more apparent.

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RealNC
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Re: BenQ XL2411P scrolling horizontal lines

Post by RealNC » 09 May 2018, 00:39

Have you tried different cable?
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TheOneAndOnlyJP
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Re: BenQ XL2411P scrolling horizontal lines

Post by TheOneAndOnlyJP » 09 May 2018, 01:07

RealNC wrote:Have you tried different cable?
No, but while on 120hz turning instant mode back on reduces the visibility of the lines almost entirely on the screen. If I bob my head up and down I can see slight artifacts but it's drastically reduced. I am still concerned with the fact that I cannot use my monitor normally without having a mode turned on.

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Chief Blur Buster
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Re: BenQ XL2411P scrolling horizontal lines

Post by Chief Blur Buster » 10 May 2018, 13:59

Instant mode is the essentially bufferless mode (cable scanout in full sync to panel scanout). This can reduce opportunity for processing for improved image quality.

This may be LCD inversion pattern changes that occur, see http://www.testufo.com/inversion

Useful context thread: viewtopic.php?f=19&t=3629

Inversion artifacts often moves slower at a lower Hz, you mentioned it moves slower at 120Hz.

It's possible that Instant Mode affects inversion algorithms, creating different visibilities of inversion artifacts.

Also try testing odd-pixel-step www.testufo.com motion (more visible inversion artifacts) versus even-pixel-step TestUFO motion (more invisible inversion artifacts). For example, test 1200pps for 144Hz and test 960pps for 120Hz, if testing out even-pixel-step.
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TheOneAndOnlyJP
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Re: BenQ XL2411P scrolling horizontal lines

Post by TheOneAndOnlyJP » 11 May 2018, 12:06

Chief Blur Buster wrote:Instant mode is the essentially bufferless mode (cable scanout in full sync to panel scanout). This can reduce opportunity for processing for improved image quality.

This may be LCD inversion pattern changes that occur, see http://www.testufo.com/inversion

Useful context thread: viewtopic.php?f=19&t=3629

Inversion artifacts often moves slower at a lower Hz, you mentioned it moves slower at 120Hz.

It's possible that Instant Mode affects inversion algorithms, creating different visibilities of inversion artifacts.

Also try testing odd-pixel-step http://www.testufo.com motion (more visible inversion artifacts) versus even-pixel-step TestUFO motion (more invisible inversion artifacts). For example, test 1200pps for 144Hz and test 960pps for 120Hz, if testing out even-pixel-step.
Another thing I noticed is that when I change the display mode outside of "Full", the moving lines don't appear, so it's only happening in full screen mode. Also, the YouTube link I sent above describes what I'm seeing perfectly.

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lexlazootin
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Re: BenQ XL2411P scrolling horizontal lines

Post by lexlazootin » 11 May 2018, 21:12

I've seen this in a few 144hz monitors. I assume it's just a panel limitation and it's some sort of inversion artifact? I believe it happens more during hot weather.

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RealNC
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Re: BenQ XL2411P scrolling horizontal lines

Post by RealNC » 12 May 2018, 04:48

I would RMA this. This should be treated as a defect.
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lexlazootin
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Re: BenQ XL2411P scrolling horizontal lines

Post by lexlazootin » 12 May 2018, 05:29

I don't think it's a defect. I'm pretty sure this happens on quite a few panels specifically. You can see it on 60hz panels when they get hot or overclock them to 75 for a little bit.

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Re: BenQ XL2411P scrolling horizontal lines

Post by RealNC » 12 May 2018, 05:31

lexlazootin wrote:I don't think it's a defect. I'm pretty sure this happens on quite a few panels specifically. You can see it on 60hz panels when they get hot or overclock them to 75 for a little bit.
Looks like a defect to me. Or would you like to sit in front of a monitor that looks like this for the next half a decade or more? :P

If this is not a defect and the monitor ships looking like that on purpose, then I'm sorry, the company who makes it should not be allowed to make monitors. This is atrocious and unacceptable.
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lexlazootin
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Re: BenQ XL2411P scrolling horizontal lines

Post by lexlazootin » 12 May 2018, 07:20

Acer:

"In regards to the scanline issue, I have been provided with an update. Scanlines are an effect caused by rapidly changing refresh rate. Variations in the refresh rate create an increased holding time that results in the accumulation of an electrical charge. When this charge is released, it causes small variations in the frame that result in faint horizontal lines. We certainly appreciate everyone’s patience and the feedback that has been provided by many of you. Unfortunately, this is a side effect for cutting edge technology and while there is not a fix to be applied, we will continue to make efforts to minimize and eliminate these types of limitations in future releases."

If you RMA it there's a good chance it's going to have the same problem, if you want a monitor without this problem you'll have to get a monitor with a different panel that doesn't have this effect.

I just don't see this as "defective" because all of the all of the panels have this trait, you bought a product with a shitty design, the product itself is not defective.

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