Now let me try to help the original poster.
Lessee if I can figure this out...
exigeous wrote:Been pulling my hair out - I just got the new Samsung CHG90 49" super-ultra-mega-monster-amazing wide screen (basically 2 27" 1080p displays in one frame).  It's a 3840x1080 144hz display with HDR.  I also have an older Samsung 1080p 60hz display that I'm replacing (and will use as a secondary display).
When I run the tests here it shows 144hz - but in games/etc. it absolutely does NOT look like it - there's the same level of "blur" that I'm seeing on my 60hz display.  Here's what I've verified:
- Windows control panel is set to 144hz
- Nvidia control panel is set to 144hz
- If I change either to 120 as a test the site here reports 120 (but visually in games no difference)
- RTX 2080 Ti video card, i7 8086K, 32GB RAM, NVMe SSD (not a pretty beefy system)
- Displayport 1.2 cable (the one that came with the monitor)
- Tested 2 other 1.2 cables
- Upgraded the firmware on the monitor
- Am only running the one display (disconnected my old monitor)
- Tested different ports on video card
- Testing in a number of games (Doom, Project Cars, Elite Dangerous)
- Created a custom resolution of 3840x1080 with 140hz refresh (again tests show yes but no difference visually)
- Tried "Normal", "Fast" and "Faster" response times in the monitor options
- Set the monitor to 120hz and 100hz to see - again tests show it's fine but no dice.
What the hell am I missing?  I even shot some video with my cell phone to show some friends (all playing Elite Dangerous) and on their 144hz monitors they are reporting it looks MUCH better than what I'm seeing.
OK, now getting hands dirty.
Lemme try to help you...
You've clearly heeded some of the advice already, so let's begin troubleshooting.  I always love a good challenge.
(Even if it simply traces to vision abilities...but let's not leave any stone unturned)
First a word to everyone about minor motion-insensitivity vision behaviours
REMEMBER: Almost 10% of males in human population is at least partially colorblind. (
8% statistic)
Likewise, there is also something called "
motion blindness" that is often undiagnosed.  Science has shown that some people are motionblind.  If you have never been diagnosed on this, then you probably aren't, but weirder things have happened with some human vision.  You just simply might be slightly less sensitive to motion than usual, despite having better-than-average vision resolution.
Motion Blindness Exists -- and sometimes there are very weak borderline cases --
There's even "borderline" cases that go undiagnosed:
- People who are less sensitive/picky about color.  Not colorblind, just less sensitive to color.
- People who are less sensitive/picky about motion.  Not motionblind, just less sensitive to motion.
Anyway, what I've heard is there are many borderline cases that are so weak that it's not even called "motion blindness".  One is not always diagnosed by doctor to realize you might be slightly less sensitive to a certain thing.  
Not everyone can hear as well as another.  But because one might hear only 10% less, doesn't mean they have enough hearing loss to be called "deaf".  Because they still have most of your hearing.   Likewise, same for a vision attribute.   
There's someone who had better-than-average vision (resolution) but lower-than-average motion sensitivity.  I don't know if that affected you.  Maybe not.   Who knows?   Sort of akin to hearing where someone can be more sensitive of high sounds but insensitive to low sounds (or vice versa etc).  Surprising unexpected tradeoffs often occur.   Color insensivities or the use of different photoreceptors (e.g. night vision photoreceptors versus daytime vision photoreceptors) can result in modified sensitivity to motion resolution, for example.  Different humans have differing ratios of nightvision:colorvision photoreceptors, and this can also create motion sensitivity differences between different humans.
Likewise, not everyone can "see" a specific thing as well as another.  A person's vision might be 20/20 but could be 20/25.  Very minor vision impairment.  That often doesn't even warrant glasses.  You're not blind if you have 20/25 vision instead of 20/20.  Likewise, there's even minor insensitivities to motion detection.  
Alas, it is a poorly studied science.  Eye doctors don't test for degrees of motion sensitivity.  Different people have different sensitivities to refresh rates.  And sometimes it's a specific "thing" that is seen (e.g. motion.  Or color.  Or focus.  Or whatever.  Including cases that are only weak, like people who are only slightly less sensitive to motion.  Small amounts of insensitivity tends to be all perfectly normal, it's just amazing how vision is different from human to human -- even in 10% amounts.   So I've learned it's silly to criticize another vision.   Please, understand the same, too.
So it's wholly possible for a human to have better-than-average 
resolution vision (e.g. 20/12) but worse-than-average 
motion vision (hard to test precisely).
My point is....don't attack someone for not seeing 144Hz
Regardless, Please Do Not Make Fun Of Disabilities / Inabilities / Difficulties, Forum Members.
Remember, I am deaf myself since birth; I never used a telephone until age 15.
Now jawdropped forum reader, pick up the jaw (Since you didn't know Chief Blur Buster is a deafie), and read on.
Maybe it's a monitor problem, but.... HEY.  I'm Chief Blur Buster.  
I love to troubleshoot.  Track down why someone can't benefit from 144Hz.  
Maybe it's a monitor problem.  Maybe it's a VA problem.  
Maybe it's an ordinary undiagnosed vision problem (hey, nothing to be ashamed).   Maybe you're just less sensitive to motion than the average human (and nothing to be ashamed about -- it's your human brain after all).   But let's try to troubleshoot and test things out.
Maybe it's something else totally.  
Let's try to figure it out, shall we....?  
 
Blur Busters is a place of open mind.  
We are the place that found benefits of <1ms.  
We are the place that discovered great benefits of >480Hz. 
We are the place that popularized benefits of blur reduction (LightBoost and its spinoffs: ULMB, DyAc, ELMB, etc) 
We are the place that explains a lot of display phenomena well including our wonderful TestUFO tests.
We also discovered "the importance of the millisecond" that many others disbelieved.
So, we always keep an open mind around here.
OK....
QUESTIONS:
1. When you look at http://www.testufo.com at 120Hz, can you tell the UFOs apart?
a. If 120fps UFO is roughly twice as sharp as 60fps UFO.... 
...Then your TestUFO is working normal and we need to diagnose other things (game, mouse, etc).
b. If 120fps UFO is only slightly sharper than 60fps UFO... 
...Then your VA panel pixel response is probably too slow for good 120Hz+.  That said, if your room is freezing cold, warm the screen up for 30 minutes.  Cold VA panels will tend to ghost very badly, muddying 60Hz-vs-120Hz
c. If 60fps and 120fps UFO look exactly as sharp as each other....
...Then we've got an interesting behavior we need to diagnose more.  Can you please run a Frameskipping test at http://www.testufo.com/frameskipping .... follow the instructions and then post a photo.  Frameskipping can explain lack of difference between 60Hz and 120Hz.
2. What kind of games do you play?   Some games don't showoff 120Hz or 144Hz very well
Many games don't do a good job at running at 144Hz.  Also, have you tested keyboard strafe left/right instead of mouse turn left/right?
(mouse weak link, see below).  Once you list the name of the games -- we will focus on testing games that showoff maximal motion quality.
3. A bad mouse can kill 144Hz.  Are you using a 1000Hz mouse with original manufacturer mouse drivers?
Mouse microstutter can interfering with high-Hz benefit.  A stuttery mouse and/or mousepad can eliminate difference between 60Hz and 144Hz.  Even for window dragging!   One good way to smooth mouseturn motion is adjusting to somewhat higher mouse DPI sensitivity (in Control Panel) and lower sensitivity (in game).   Different mice is very finicky about how well they work at various DPI, and it's a personal preference.  However, it's good to read the 
Blur Busters Mouse Guide and make sure it's not the weak link.
4. Are you staring stationary at crosshairs (while things move past) -- or are you tracking eyes on moving objects?
Higher hertz benefits behave differently in these situations.  Playing a crosshairsless game such as Rocket League (and always moving eyes on moving objects) can lead to a different feel of high-Hz than playing a crosshairs game such as CS:GO (and staring mostly stationary).   We've accidentally discovered that some people become motion-insensitive in only one of the two situations.   Personally, I'm sensitive to both, but some people appears to be sensitive to high-Hz in one or other situation.
Side Advanced Note: Although below article is for blur reduced modes, it has some neat animations relevant to #4 above:
Related topic: How to use ULMB Competitively And Beautifully.
That demonstrates different visual behaviours of stationary eyes versus moving eyes.  Subsequently, over the years, we've anecdotally discovered that it seemed about ~1% to ~10% of people see a different motion behaviour than ~90% to ~99% of other people (Exact percentages unknown, but it certainly wasn't behaving the same with all human eyes on the same display) ...when they stare at the optical illusions I've invented at TestUFO Eye Tracking Animation or TestUFO Persistence Animation  -- try these amazing optical illusions out.  Displays behave differently for your eyes depending on stationary-gaze (crosshairs) versus moving-object (tracking eyes on motion).   Few scientific papers exist (gaming display research and eSports research) but maybe some other lurking researcher wants to do their Masters/P.hD or thesis on this sort of vision research topic?
RealNC may be straight to the point, and he may be very well right, but I don't leave stones unturned.
Let's see if we can crack this mystery.  Monitor fault, driver fault, vision quirk, bad mouse, multiple factors, etc.