Overclockable IPS Monitor

Talk about overclocking displays at a higher refresh rate. This includes homebrew, 165Hz, QNIX, Catleap, Overlord Tempest, SEIKI displays, certain HDTVs, and other overclockable displays.
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ChvyKc
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Overclockable IPS Monitor

Post by ChvyKc » 11 Feb 2014, 09:16

I started looking into overclockable monitors because I tend to struggle with motion sickness while playing games at 60Hz. Games like Assassin's Creed 4 and Borderlands 2 cause me to quit playing after about 20 minutes. I get a small headache and become very nauseous.

I currently have a Dell IPS monitor that I can only overclock to 65Hz before the annoying error message appears telling me I'm trying to fry my monitor. I see no difference at all between 60 and 65. I was able to borrow a LG IPS monitor from a coworker (benefits of working in the IT department) and I was able to overclock it to 74Hz. This made a huge difference and I was able to play for over two hours with no problems.

I love the quality my IPS monitor gives me so I would really like to stay with an IPS panel. My question is, are there any other IPS monitors that you guys know of that I can overclock higher than 74Hz?

Black Octagon
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Re: Overclockable IPS Monitor

Post by Black Octagon » 11 Feb 2014, 13:05

Yep, 2 that go to approx 120Hz:

Overlord Tempest X270OC

and

Yamakasi Catleap Extreme 2B

Running these monitors at 120Hz substantially improves motion blur compared to 60Hz but there is still a little more blur than TN displays that can run native 120Hz (due to pixel persistence caused by the slow response time of the IPS panel).

As Mark explained it to me, your screen's pixel transition time - the real one, not the manufacturer's declared pixel response time - needs to be at least as fast as 50% of the display refresh time in order for pixel persistence to no longer be a real issue. So, art 120hz the display refresh time is 8.33ms. 50% of that is a little over 4ms. Unlike gaming TNs, IPS panels cannot do pixel transitions faster than 4ms, so at 120hz there is done added motion blur. It's still a glorious experience, but a definite notch or so behind Lightboost/ULMB

Sent from dumbphone (pls excuse typos and dumbness)

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Re: Overclockable IPS Monitor

Post by Chief Blur Buster » 11 Feb 2014, 13:33

Black Octagon wrote:As Mark explained it to me, your screen's pixel transition time - the real one, not the manufacturer's declared pixel response time - needs to be at least as fast as 50% of the display refresh time in order for pixel persistence to no longer be a real issue.
I didn't say "real issue" --
It just ceases to be the dominant problem for motion blur

So this is what I actually meant: "Once the pixel transition is significantly than a refresh cycle, GtG ceases to be the motion blur limiting factor".

Note: persistence (pixel static state) is different from transitions (pixel movement).
Pixel _persistence_ is still an issue even at 0ms instant pixel transitions.
Even 2ms persistence still has noticeably more motion blur than 1ms persistence.
However, 2ms GtG does not have noticeably more motion blur than 1ms GtG, since persistence is the dominant factor.
Black Octagon wrote:Unlike gaming TNs, IPS panels cannot do pixel transitions faster than 4ms, so at 120hz there is done added motion blur.
False.
I CAN see motion blur differences between 0.5ms, 1.0ms, 2.0ms, 3.0ms, and 4.0ms persistence.
I CAN'T see motion blur differences between 0.5ms, 1.0ms, 2.0ms, 3.0ms, and 4.0ms GtG.
Persistence is more important than GtG in motion blur.
GtG just ceases to be the motion blur limiting factor when it's less than 50% of a refresh cycle.
The baton of the dominant motion blur limiting factor transfers over to persistence, which is bottlenecked at the frame visibility length. e.g. Most 2ms LCDs have 16.7ms of persistence. (Good demo of persistence: http://www.testufo.com/eyetracking ...)

Mathematically, 1ms equals 1 pixel of motion blurring during 1000 pixels/second (e.g. http://www.testufo.com/photo ).
0.5ms persistence = 1 pixel of motion blur during 2000 pixels/second motion
1ms persistence = 1 pixel of motion blur during 1000 pixels/second motion
2ms persistence = 1 pixel of motion blur during 500 pixels/second motion
4ms persistence = 1 pixel of motion blur during 250 pixels/second motion
or conversely,
0.5ms persistence = 0.5 pixel of motion blur during 1000 pixels/second motion
1ms persistence = 1 pixel of motion blur during 1000 pixels/second motion
2ms persistence = 2 pixel of motion blur during 1000 pixels/second motion
4ms persistence = 4 pixel of motion blur during 1000 pixels/second motion

However, manufacturers rate in GtG (pixel transition speed), but not in persistence (pixel visiblilty time during a frame).
There's only two effective ways to lower persistence:
1. Shorten pixel visibility by strobing (black frame insertion, strobing, etc)
2. Shorten pixel visibility by increasing number of frames (120fps@120Hz, 240fps@240Hz)

As you track moving objects with your eyes on a display, your eyes are in a different position at the beginning of a visible refresh than at the end of the visible refresh. This is because your eyes are continuously moving, while the frames themselves stay static during a refresh cycle. Tracking moving objects on a 60Hz flickerfree display, is metaphorically equivalent to trying to take a camera photograph with 1/60sec shutter while panning the camera: Blurry photograph. The longer time a static pixel is visible for, the more motion blurring will occur (Example: http://www.testufo.com/eyetracking ). Now if you flash the backlight for only 1ms (e.g. LightBoost 10%), the backlight is metaphorically equivalent to a 1/1000sec camera shutter -- keeping things sharp during fast motion.

So, again, motion blur is still a problem even at 2ms persistence, 3ms persistence, 4ms persistence. It's just that the manufacturers rate using the transition formula (grey-to-grey pixel movement) rather than the persistence formula (pixel static/visible state == sample-and-hold effect == persistence), and motion blur is directly proportional to persistence.

This is a simplified example of what was happening over the last 10 years:

33ms GtG LCDs -- about 33ms+ of motion blur at 60Hz (often worse)
25ms GtG LCDs -- about 25ms+ of motion blur at 60Hz (often worse)
16ms GtG LCDs -- about 16.7ms+ of motion blur at 60Hz (often worse)
8ms GtG LCDs -- about 16.7ms+ of motion blur at 60Hz (often slightly worse)
5ms GtG LCDs -- about 16.7ms of motion blur at 60Hz (very accurately 16.7ms of motion blur)
4ms GtG LCDs -- about 16.7ms of motion blur at 60Hz (very accurately 16.7ms of motion blur)
2ms GtG LCDs -- about 16.7ms of motion blur at 60Hz (very accurately 16.7ms of motion blur)
1ms GtG LCDs -- about 16.7ms of motion blur at 60Hz (very accurately 16.7ms of motion blur)

(1/60 second equals 16.7ms, and that's 16.7 pixels of motion blur during 1000 pixels/second motion).

Motion blur is bottlenecked by persistence once GtG dips below half a frame cycle. Meaning, there is a motion blur problem even with 1ms LCDs, because of the persistence problem (sample-and-hold effect), as demonstrated by the animation at http://www.testufo.com/eyetracking
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ChvyKc
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Re: Overclockable IPS Monitor

Post by ChvyKc » 11 Feb 2014, 13:42

That is a lot of information. Probably a little more than I can comprehend to be honest. :D

I do appreciate the responses and I'm torn between two monitors.

LG 23EA63 - IPS monitor that I can overclock to 74Hz
ASUS VG248QE - Really don't want to give up IPS panel but that refresh rate is very tempting

Honestly, I'm not really feeling a 27" monitor and I definitely don't want to spend the cash on one.

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Re: Overclockable IPS Monitor

Post by Chief Blur Buster » 11 Feb 2014, 13:57

Here's some information additional information for you to consider 120Hz strobed versus 120Hz non-strobed:

- 60 Hz versus 120 Hz versus LightBoost
- LightBoost media coverage
- LightBoost testimonials

Generally:
60Hz -- baseline
120Hz -- 50% less motion blur than 60Hz
LightBoost -- 90% less motion blur than 60Hz
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

       To support Blur Busters:
       • Official List of Best Gaming Monitors
       • List of G-SYNC Monitors
       • List of FreeSync Monitors
       • List of Ultrawide Monitors

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Re: Overclockable IPS Monitor

Post by Chief Blur Buster » 11 Feb 2014, 15:30

Oh, and I forgot to mention, Blur Busters now has an Overclockable 1440p 120Hz IPS/PLS Monitor Guide. Go check it out!
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       To support Blur Busters:
       • Official List of Best Gaming Monitors
       • List of G-SYNC Monitors
       • List of FreeSync Monitors
       • List of Ultrawide Monitors

spacediver
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Re: Overclockable IPS Monitor

Post by spacediver » 11 Feb 2014, 16:12

Chief Blur Buster wrote: This is a simplified example of what was happening over the last 10 years:

33ms GtG LCDs -- about 33ms+ of motion blur at 60Hz (often worse)
25ms GtG LCDs -- about 25ms+ of motion blur at 60Hz (often worse)
16ms GtG LCDs -- about 16.7ms+ of motion blur at 60Hz (often worse)
8ms GtG LCDs -- about 16.7ms+ of motion blur at 60Hz (often slightly worse)
5ms GtG LCDs -- about 16.7ms of motion blur at 60Hz (very accurately 16.7ms of motion blur)
4ms GtG LCDs -- about 16.7ms of motion blur at 60Hz (very accurately 16.7ms of motion blur)
2ms GtG LCDs -- about 16.7ms of motion blur at 60Hz (very accurately 16.7ms of motion blur)
1ms GtG LCDs -- about 16.7ms of motion blur at 60Hz (very accurately 16.7ms of motion blur)
thanks, this is a very nice way of explaining it.

Black Octagon
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Re: Overclockable IPS Monitor

Post by Black Octagon » 11 Feb 2014, 16:28

Thanks for the clarifications Mark. My noob paraphrasing is surely no substitute for an explanation by the original source

Sent from dumbphone (pls excuse typos and dumbness)

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