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Re:Computer input latency from 1977-2017 (2017) by Jonnax on Thursday December 03, 2020 @11:37AM (#25290728)
Anyone that has used a 120Hz+ display will immediately notice that everything feels more responsive even with simple things like moving your mouse and scrolling.

I also find the responsiveness noticeable when typing. You'll be able to tell that the text appears faster on the screen.

I wouldn't say it's a requirement. But it does make the user experience nicer.

Re:Computer input latency from 1977-2017 (2017) by rsanheim on Thursday December 03, 2020 @01:16PM (#25292363)
Now if only someone made a 34” ultra wide with 120Hz+. In particular one with 5120 x 2160 resolution. Maybe in 2022 at the rate high hertz monitors are coming for non-gaming uses...
Re:Computer input latency from 1977-2017 (2017) by ezluckyfree on Thursday December 03, 2020 @01:22PM (#25292455)
I agree. I'd rather hi-dpi 32"+ monitors first though. Hidpi displays are becoming standard on top-end laptops but on desktop you're almost out of luck.

It's wild that the only hidpi 32" monitor is ~$5000, and it was released a few years ago now.

My eyeballs need that sweet crisp text.

Re:Computer input latency from 1977-2017 (2017) by kllrnohj on Thursday December 03, 2020 @01:28PM (#25292527)
What are you calling "hi-dpi"? There's a ton of 4k monitors in the 27" to 32" range, which are definitely higher DPI than typical. And for a lot less than $5000.
Re:Computer input latency from 1977-2017 (2017) by ezluckyfree on Thursday December 03, 2020 @01:47PM (#25292805)
I'm typing this on a 4k, 32" monitor, which is 137.68 DPI, but I also have a Dell XPS 15, which is 4K and 15", 293.72 DPI, and the difference in sharpness is astounding.

The other problem with hidpi scaling (200%) at 4k 32", is that everything is huge, and you lose a lot of screen real estate.

Honestly I think 8k 36" is the sweet spot.

Re:Computer input latency from 1977-2017 (2017) by GuB-42 on Thursday December 03, 2020 @03:44PM (#25294560)
DPIs don't mean anything unless you factor in viewing distance.

In fact, it is common to recommend a vertical viewing angle of 30 degrees. Not more as it tends to increase eye fatigue and neck pain. If you follow that recommendation, what matters is the definition (the number of pixels), not the resolution in DPI.

So, let's run a few calculations. The "retina" resolution is based on a pixel size of 1 arc-minute, that's 20/20 vision, at 30 degrees, that's 1800 pixels. 4k is 2160 vertical, so that's about the limit of human vision. So, basically, 4k is what you want at any size.

8k is not useless but you are pushing the boundaries here. In order to notice it, you need perfect, over 20/20 vision, high luminosity and high contrast. Beyond 8k, you enter superhuman territory, with an exception: you can notice discontinuities at a much higher resolution (vernier resolution), but it only matters if you don't have anti-aliasing. And of course, high contrast, luminosity and perfect vision.

There are exception. For example there is a limit on how close a screen can be, so having 4k on a tiny smartphone screen is mostly useless. The other end of the spectrum would be VR, with fields of view over 100 degrees, 8k per eye is considered a minimum for an immersive experience.

Re:Computer input latency from 1977-2017 (2017) by ezluckyfree on Thursday December 03, 2020 @04:03PM (#25294888)
>So, let's run a few calculations. The "retina" resolution is based on a pixel size of 1 arc-minute, that's 20/20 vision, at 30 degrees, that's 1800 pixels. 4k is 2160 vertical, so that's about the limit of human vision. So, basically, 4k is what you want at any size.

No, because I don't want to move my 32" monitor further away to get that 30 degree viewing angle. The reason I have a 32" monitor for work is to have more screen real estate. A 30 degree viewing angle works for watching movies and stuff, but when I use it for coding, I essentially have multiple 30 degree viewing (on-screen) windows.

You might say "ok well just get two or three monitors", but that isn't the same either. Besides the space between the monitors, with one large monitor I can subdivide my screen space in any way depending on what I'm doing, where each window has a 10-30 degree viewing angle or whatever.

>you can notice discontinuities at a much higher resolution (vernier resolution), but it only matters if you don't have anti-aliasing.

That's just not true though. It does matter even with antialiasing, the difference is clear. In particular, the dell xps 15 2019 has a ~290 dpi OLED, which has high contrast.

Re:Computer input latency from 1977-2017 (2017) by GuB-42 on Thursday December 03, 2020 @04:39PM (#25295488)
30 degrees vertical is actually a recommendation for work[1], not for movies. If you look around for guide about ergonomics, you will often see that 30 degrees figure, or "top of the screen at eye level, center 15 degrees down", which mean the same thing.

For movies, THX recommends a 36 degrees horizontal viewing angle[2], which is about 20 degrees vertical. Recommendations vary, sometimes it is 30 degrees, sometimes it is 40, but always horizontal.

Now, no one will force you. If you prefer to have a very large screen right up your nose, that's your choice, and maybe your work environment calls for it. But it is just not what it is generally recommended and I would put it into the "exception" category. And sure, in that case, increased resolution is good.

As for antialiasing, it will not make the image sharper, quite the opposite in fact. However, if your resolution is so that it is over your visual acuity (you can't distinguish between 2 thin parallel lines and 1 thicker line), antialiasing will take care of superaccuity. That's the ability of your brain to use image processing techniques to detect jaggies that are finer than what you eye can see. If you have good vision and a 4k monitor closer to you than the recommended distance, it is normal to see the difference even with anti-aliasing turned on.

[1] https://www.viewsonic.com/library/business/best-computer-scr...

[2] https://www.thx.com/questions/thx-certified-screen-placement...

Re:Computer input latency from 1977-2017 (2017) by wtallis on Thursday December 03, 2020 @10:57PM (#25298713)
If the recommended horizontal viewing angle for a movie is 36 degrees, why is it hard for you to understand wanting a desktop PC display with significantly larger field of view, given that large PC displays are used subdivided into multiple windows? There's real usability value for a PC display that extends further into your peripheral vision than a movie screen, because you don't actively watch the whole PC screen at once.
Re:Computer input latency from 1977-2017 (2017) by coldtea on Thursday December 03, 2020 @11:14PM (#25298841)
>DPIs don't mean anything unless you factor in viewing distance.

Between phone, table, and laptop, monitor, yes.

But when speaking of monitors alone, it's not that relevant an observation in practice, since most monitors, whether 27", or 32", or 24" are seen from more or less the same distance.

Re:Computer input latency from 1977-2017 (2017) by 0-_-0 on Friday December 04, 2020 @09:34AM (#25302594)
> 4k is 2160 vertical, so that's about the limit of human vision.

This is false. Misalignment of borders can be detected with a precision up to 10 times better than visual acuity [0], therefore your numbers should be multiplied by 10, meaning 40K is the optimal screen resolution, or 80K for people with particularly good vision.

[0] https://en.wikipedia.org/wiki/Hyperacuity_(scientific_term)

Re:Computer input latency from 1977-2017 (2017) by GuB-42 on Friday December 04, 2020 @03:16PM (#25307206)
It assumes no anti-aliasing.

Anti-aliasing is the display counterpart of hyperperacuity.

Here is a paper: https://www.researchgate.net/publication/320353446_Effects_o...

Its conclusion is that with anti-aliasing, you only need half the resolution to reach the detection threshold for misalignment of borders compared to other visual acuity tests.

Re:Computer input latency from 1977-2017 (2017) by abstractbarista on Friday December 04, 2020 @10:15AM (#25303117)
I always noticed I could do this, but wasn't sure what it was called. Thank you!
Re:Computer input latency from 1977-2017 (2017) by patrickthebold on Thursday December 03, 2020 @02:08PM (#25293087)
Why scale it if you think that makes me everything huge? I don't do the scaling and enjoy the extra real estate.
Re:Computer input latency from 1977-2017 (2017) by coldtea on Thursday December 03, 2020 @11:16PM (#25298858)
Because then you lose the sharpness, and the extra real estate is too much, so everything is both less sharp AND tiny.
Re:Computer input latency from 1977-2017 (2017) by ezluckyfree on Thursday December 03, 2020 @02:11PM (#25293153)
I don't scale it, but then I lose the text sharpness. I would like both.
Re:Computer input latency from 1977-2017 (2017) by opan on Thursday December 03, 2020 @05:11PM (#25295895)
You could use bitmap fonts to get truly sharp text. I'm a big fan of terminus at 9pt. It makes non-bitmap fonts look blurry and awful by comparison. A real shame that Pango broke bitmap support and your choice of terminal emulator and other stuff is limited now.
Re:Computer input latency from 1977-2017 (2017) by swiley on Thursday December 03, 2020 @05:14PM (#25295936)
IMO this is a huge and underrated advantage of bitmapped fonts.

The problem is that you need a font at exactly the right scale to realize this advantage. The right scale is often different for every user/monitor pair and changing the scale means redrawing the font which is a ton of work.

Re:Computer input latency from 1977-2017 (2017) by buran77 on Thursday December 03, 2020 @03:37PM (#25294434)
To keep the same pixel density you'd need an 8K at 30" or 10K at 36". I'm sure we'll get there but not anytime soon, at least not at prices almost anyone would be willing to pay, or not without sacrificing other specs that you surely want.
Re:Computer input latency from 1977-2017 (2017) by ezluckyfree on Thursday December 03, 2020 @03:47PM (#25294620)
Yeah, I know.

I'd be happy with like 8k at 34" or so.

Re:Computer input latency from 1977-2017 (2017) by kllrnohj on Thursday December 03, 2020 @02:38PM (#25293550)
There's settings other than 100% and 200%. Set it to 125%. Or 150%.
Re:Computer input latency from 1977-2017 (2017) by ezluckyfree on Thursday December 03, 2020 @03:46PM (#25294594)
That is not the same. Non-integer scaling results in worse sharpness because of the way it needs to be implemented.

See eg: https://tonsky.me/blog/monitors/

Re:Computer input latency from 1977-2017 (2017) by kllrnohj on Thursday December 03, 2020 @04:10PM (#25294981)
That's not true at all. Fonts & other vector-based graphics scale to any resolution just fine.

The myth of 1x, 2x, and 3x being "preferred" is just an Apple-ism because their UI toolkit is pixel-based. That's a flaw in their toolkit, not an inherent technical constraint. Combined with then Apple scaling it yet again after it's rendered.

Other platforms are not nearly as badly designed.

Re:Computer input latency from 1977-2017 (2017) by coldtea on Thursday December 03, 2020 @11:19PM (#25298891)
>The myth of 1x, 2x, and 3x being "preferred" is just an Apple-ism because their UI toolkit is pixel-based. That's a flaw in their toolkit, not an inherent technical constraint. Combined with then Apple scaling it yet again after it's rendered.

Apple-ism? Please. Most plarforms and GUI libs are pixel based, and we always have photos to see and other such bitmap assets.

Re:Computer input latency from 1977-2017 (2017) by kllrnohj on Friday December 04, 2020 @09:05AM (#25302307)
Your photos rarely if ever match the size they are displayed at anyway. What Apple does is the worst possible thing for your photos, which typically end up double resized (once to the app's internal size, then once again for the display scaling).

The largest platform, Android, is not pixel based. The largest desktop platform, Windows, also went through the effort to try and do things properly here, letting the app handle DPI instead and then providing updated toolkits to do that automatically.

Re:Computer input latency from 1977-2017 (2017) by LukeShu on Thursday December 03, 2020 @04:44PM (#25295561)
> The myth of 1x, 2x, and 3x being "preferred" is just an Apple-ism

And a GTK-ism.

Re:Computer input latency from 1977-2017 (2017) by ClumsyPilot on Thursday December 03, 2020 @09:05PM (#25298092)
You are not getting any 'sharpness benefit' if your 4k display is showing an upscaled 1080p image.

All applications i use on windows support scaling natively, and provide crisp text at 150%. It's not 2010 any more, this is a solved problem. Anything that doesnt should be killed with fire.

Re:Computer input latency from 1977-2017 (2017) by turtlebits on Thursday December 03, 2020 @02:02PM (#25292993)
I have the same displays as you- Dell 4k @ 15" and currently using a 32" 4k (I sit 2ft away from it). I also have a Macbook Pro 16 (3072×1920). I honestly don't see a substantial difference between any of them, and I'm generally pretty picky about resolution.
Re:Computer input latency from 1977-2017 (2017) by ezluckyfree on Thursday December 03, 2020 @02:14PM (#25293188)
Right but if you scale the 32" so you get the hidpi sharpness (and put it far away), you lose the real-estate that you could have on a 32" screen.
Re:Computer input latency from 1977-2017 (2017) by FpUser on Thursday December 03, 2020 @03:32PM (#25294372)
I use 4K 32" with scaling at 100% and it seems totally fine. Lots of real 15-17" laptop screen at 4K makes no sense to me as I can't use 100% as the text size becomes too small.
Re:Computer input latency from 1977-2017 (2017) by ezluckyfree on Thursday December 03, 2020 @03:55PM (#25294767)
Right, the whole idea is that you use 200% and get that really crisp text.
Re:Computer input latency from 1977-2017 (2017) by FpUser on Friday December 04, 2020 @05:32AM (#25300894)
What I have already feels crisp enough and since I do a lot of programming I'd rather see more lines of code than increase scaling for no real benefits. As a matter of fact one of the 2 4K monitors on my desk is in portrait mode just for that.
Re:Computer input latency from 1977-2017 (2017) by oblio on Thursday December 03, 2020 @02:09PM (#25293112)
You shouldn't be as close to the laptop screen as to the big monitor. And at larger distances the pixel densities can be lower.
Re:Computer input latency from 1977-2017 (2017) by ezluckyfree on Thursday December 03, 2020 @02:13PM (#25293174)
This is the argument that HiDPI displays are pointless if you're not very close to the monitor, and if you've used a retina display, you know that there is absolutely a difference.
Re:Computer input latency from 1977-2017 (2017) by oblio on Thursday December 03, 2020 @04:31PM (#25295345)
You probably hold your phone about 30-40cm from your face. You probably look at your laptop screen at 50-60. You should be at least 75cm it not 90 or 100cm away from a big monitor.

I'm not convinced the difference is obvious.

Re:Computer input latency from 1977-2017 (2017) by LukeShu on Thursday December 03, 2020 @04:46PM (#25295576)
Did you say that backwards? On my lap, the screen of my laptop is 17"-20" from my face. At a desk, the monitor is usually about 28" from my face.
Re:Computer input latency from 1977-2017 (2017) by oblio on Thursday December 03, 2020 @05:12PM (#25295914)
Yeah, I might have :-)

You should be farther from your monitor than you are from your laptop.

Re:Computer input latency from 1977-2017 (2017) by ineedasername on Thursday December 03, 2020 @11:04PM (#25298757)
It's that you have to go to such a larger screen size. I just upgraded my monitor from a 1080p. I really wanted a 24" @ 4k for higher dpi and crispness. Practically impossible to find, despite being common on laptops with much smaller screens. I had to go up to 27" instead, which is still crisp, though not as much, and larger than I wanted for the space it's in.
Re:Computer input latency from 1977-2017 (2017) by fomine3 on Thursday December 03, 2020 @11:40PM (#25299033)
I need both 4K and 120/144Hz on 32inch but it's not available now. Maybe soon.
Re:Computer input latency from 1977-2017 (2017) by johnwalkr on Thursday December 03, 2020 @09:10PM (#25298129)
There was some really dark times around 2002 to 2012 where good CRTs became unavailable and almost every LCD screen was "HD" meaning 1080p. Still at the tail end of these times, I guess.
Re:Computer input latency from 1977-2017 (2017) by selestify on Friday December 04, 2020 @12:21AM (#25299291)
I suppose my lack of age here is obvious, but what made the CRTs better? Presumably they weren’t outputting any more pixels than LCDs were?
Re:Computer input latency from 1977-2017 (2017) by johnwalkr on Saturday December 05, 2020 @12:25AM (#25312026)
They were. Most tech people I knew had a 19 or 20 inch monitor, at 1600x1200 in the late 90s/early 2000s. 2048x1536 was available too. Early LCDs were usually 1280x1024 and by around 2005, larger sizes and 1080p LCDs were available. It was hard to find anything approaching the pixel density of an old, common CRT until around 2010 if I recall correctly.
Re:Computer input latency from 1977-2017 (2017) by nawgz on Thursday December 03, 2020 @02:35PM (#25293497)
Monitors like LG27GL850 are 1440p 144hz with great color repro. Not ultra-wide, but ultra-wide is not something I personally value
Re:Computer input latency from 1977-2017 (2017) by zionic on Thursday December 03, 2020 @02:54PM (#25293792)
I currently use multiple monitors, and apparently nobody at Apple HQ uses a monitor in portrait mode. Catalina routinely forgets the monitor is portrait and requires manually changing it back _every time the machine is locked_.

Why is this relevant? I'm seriously considering a 1440p 32:9 240hz Samsung G9 so that I can ditch multiple monitors and move to a single display with similar overall screen space just to dodge pesky multi-screen bugs like this. Just docking my laptop and using a massive screen would be SO NICE!

Only thing that's holding me back is I really want 2160p tall in that form factor. Will probably need to wait for DisplayPort2.0

Re:Computer input latency from 1977-2017 (2017) by e_proxus on Friday December 04, 2020 @10:50AM (#25303628)
And now the Dell Alienware AW2721D which has 240 Hz https://www.dell.com/en-ca/shop/alienware-27-gaming-monitor-...
Re:Computer input latency from 1977-2017 (2017) by cheeze on Thursday December 03, 2020 @03:05PM (#25293954)
I personally can't stand the ultrawides. OS support for a huge monitor just isn't where I'd want it to be. Sure I can install applications to handle window management better and whatnot, but even trivial things like fullscreen video don't work well at all.

I'm a huge fan of the LG27GN950. 4k 144hz glory.

Re:Computer input latency from 1977-2017 (2017) by outworlder on Thursday December 03, 2020 @03:01PM (#25293903)
There are plenty of ultra-wide monitors with greater than 120Hz refresh. Just not with the resolution you are asking for.

Or at the size you are looking for.

Samsung 49-Inch CHG90 144Hz

It's a 49 inch, so not the same PPI. Different aspect ration too (32:9, so 5120x1440).

Re:Computer input latency from 1977-2017 (2017) by rsanheim on Thursday December 03, 2020 @04:13PM (#25295034)
I'm seeing a resolution of 3840 X 1080 for that monitor?

https://www.samsung.com/us/computing/monitors/gaming/49--chg...

Thats a PPI of something like 80, which may be fine for gaming but is not at all comparable to the high PPI monitors discussed here.

Re:Computer input latency from 1977-2017 (2017) by wpm on Thursday December 03, 2020 @04:59PM (#25295767)
There's a 2x1080p version for $750 and a 2x1440p version for $999 (CRG90)
Re:Computer input latency from 1977-2017 (2017) by an_opabinia on Thursday December 03, 2020 @02:26PM (#25293369)
Re:Computer input latency from 1977-2017 (2017) by lgats on Friday December 04, 2020 @02:51AM (#25300045)
5120x1440 | 240 Hz
Re:Computer input latency from 1977-2017 (2017) by theandrewbailey on Thursday December 03, 2020 @01:30PM (#25292561)
I'm looking for something similar, but not ultrawide. There's plenty of 27" 4k 100Hz+ monitors, but not the same in 30-36" sizes. I have 3x 24" monitors, and would like to replace one or two of them with one bigger screen that's higher resolution and faster.
Re:Computer input latency from 1977-2017 (2017) by rsanheim on Thursday December 03, 2020 @02:25PM (#25293341)
Yeah I'm on an iMac Pro (which is the same display as the 27" iMacs) as my main display at its pretty glorious with 218 PPI. My older 34" ultra wide next to it is really showing its age, both in terms of overall quality and 110 PPI. The newer LG 34" that is 5K2K is not horrible at 164 psi.

If Apple just sold there 27" display for 1500 bucks or something they would make a killing for folks who want a really nice pro display but don't need the overkill of the Pro Display XDR.

Re:Computer input latency from 1977-2017 (2017) by skunkworker on Friday December 04, 2020 @02:23AM (#25299877)
My current dream monitor is a 42inch 3840x2400 or 7680x4800 - 120hz screen. I love the 16:10 aspect ratio and real estate of a monitor like that. I’m currently running 3 24inch monitors in portrait mode, so 3600x1920
Re:Computer input latency from 1977-2017 (2017) by bjoli on Friday December 04, 2020 @04:24AM (#25300511)
I am still mad that all display vendors went 16:9. The black bars are fine when watching movies if you mostly use the display for productive work, whereas 4:3->16:9 was a shitty transition for someone like me working mostly with text and written music. It was as if the world had decided that the use case for computer screens was something else than what I was using them for. Although I do costume some video content on my computer today, I would switch to a high-res 4:3 display instantly.

A 27" 4000x3000 display would be a dream come true.

Re:Computer input latency from 1977-2017 (2017) by bradstewart on Thursday December 03, 2020 @03:46PM (#25294591)
I'm waiting for the same thing. Hoping LG actually has this in the works, as their current 34" 5120 x 2160 has been out of stock for a while now, and they make a bunch of other high refresh rate displays.
Re:Computer input latency from 1977-2017 (2017) by Teknoman117 on Thursday December 03, 2020 @02:02PM (#25292989)
I am also going to be buying one of these as soon as they hit the market.
Re:Computer input latency from 1977-2017 (2017) by account42 on Monday December 07, 2020 @03:56AM (#25330476)
The LG 38GN950-B [0] gets close. 3840x1600 so not quite your wanted resolution but close - enough to fit most 4K movies if you remove the black bars. Personally I am hoping someone will make an OLED with this format.

[0] https://www.lg.com/us/monitors/lg-38gn950-b-gaming-monitor

Re:Computer input latency from 1977-2017 (2017) by methyl on Thursday December 03, 2020 @03:57PM (#25294790)
Xiaomi Surface 34
Re:Computer input latency from 1977-2017 (2017) by turtlebits on Thursday December 03, 2020 @01:55PM (#25292911)
I doubt you'll find any gaming monitors at that resolution for a while. The newest Nvidia GPUs can't hit high enough frame rates at 4k to utilize 120Hz.

Why do you need 120Hz+ for productivity?

Re:Computer input latency from 1977-2017 (2017) by gameswithgo on Thursday December 03, 2020 @02:07PM (#25293062)
1. With DLSS 2.0 you can get 120+ fps in a lot of things on the 3080 @ 4k

2. No one need do anything except die, but shaving a few ms of response time is nice for productivity. No one thing is critical but making sure you have a keyboard, mouse, monitor, refresh rate, and programs that aren't throwing latency out the window makes for an overall nice feeling system.

Re:Computer input latency from 1977-2017 (2017) by lend000 on Thursday December 03, 2020 @02:40PM (#25293588)
My understanding is that if you aren't gaming (i.e. most of the content on your screen is static) your GPU is smart enough not to redraw the entire frame so you can probably get very low latency refreshes.
Re:Computer input latency from 1977-2017 (2017) by antiterra on Thursday December 03, 2020 @06:29PM (#25296896)
Even without DLSS, this isn’t necessarily true. My 3080 has no problems pegging some recent games at 144-160 fps at the corresponding refresh rate. In fact, I’m generally CPU bottlenecked at 1440p or below.
Re:Computer input latency from 1977-2017 (2017) by Baeocystin on Thursday December 03, 2020 @04:49PM (#25295624)
I bought a 165Hz gsync screen years ago for gaming.

I bought all of my other high-refresh screens because wow computing feels so much better in the day-to-day desktop because of it! Not joking in the least.

Re:Computer input latency from 1977-2017 (2017) by ClumsyPilot on Thursday December 03, 2020 @09:10PM (#25298125)
My brother swears by his 140hz display, I have used it for a bit and came away feeling underwhelmed - I prefer my 4K 10bit 60hz display
Re:Computer input latency from 1977-2017 (2017) by Baeocystin on Thursday December 03, 2020 @11:14PM (#25298832)
I can understand if you need the pixels and bit depth for color work. I just work with sRGB, and the panel I have is fine for that. I really do like the speed, though.
Re:Computer input latency from 1977-2017 (2017) by nsxwolf on Thursday December 03, 2020 @11:41AM (#25290789)
But the text isn't making it from your keyboard through the machine and to the monitor any faster. Seems like at 120hz you're just maybe going to catch it a frame earlier when it shows up.
Re:Computer input latency from 1977-2017 (2017) by formerly_proven on Thursday December 03, 2020 @11:57AM (#25291050)
It is, because there may be multiple things synchronizing their inputs and outputs to the refresh, which causes the refresh-related latency to be a number of frames. E.g. in some Linux compositors inputs are latched with the refresh, apps themselves may render in sync, and the compositor also draws in sync; the GPU driver would also introduce at least a frame of latency typically.

Another factor is that some (many?) 60 Hz displays buffer a whole frame themselves, and often don't have quick response times. If you go from a 10 ms response time IPS screen with a frame buffer to a 120 Hz gaming screen with 2-3 ms response time, you already got a difference of about 25 ms just in the screen itself.

8 ms is hard to notice. 50 ms less so.

The difference is pretty huge, even on systems that are much better tuned than Linux desktops (e.g. Windows 10).

That being said, while it is very nice and feels nice, it's not necessary for development work; I spend most of my days developing on a system over a VNC connection through a VPN, so the basic input lag of that setup is around 200-300 ms. Gnarly yes, but not particularly bad for text input. You get used to just do everything very slowly with the mouse.

Re:Computer input latency from 1977-2017 (2017) by 1996 on Thursday December 03, 2020 @03:17PM (#25294154)
> The difference is pretty huge, even on systems that are much better tuned than Linux desktops (e.g. Windows 10).

What would you suggest, or either Windows 10 or Linux, to get the lowest latency in a terminal?

Re:Computer input latency from 1977-2017 (2017) by toast0 on Thursday December 03, 2020 @04:24PM (#25295221)
If you want the lowest latency in a terminal, use a vga textmode console with a ps/2 keyboard. That's pretty hard to get on windows 10, so I'd go with Linux.
Re:Computer input latency from 1977-2017 (2017) by copperx on Thursday December 03, 2020 @05:40PM (#25296281)
I agree. Make sure it's not a framebuffer, because it also adds latency.
Re:Computer input latency from 1977-2017 (2017) by 1996 on Saturday December 05, 2020 @10:33AM (#25315258)
Unfortunately, if you want a normal sized font, this is not possible with modern "high resolution" displays
Re:Computer input latency from 1977-2017 (2017) by hmage on Thursday December 03, 2020 @01:25PM (#25292495)
In the article: > We get a 90 ms improvement from going from 24 Hz to 165 Hz.

As per the linked article, the observed delay improvement isn't one frame, more like ~3 frames. It doesn't go up from 1/24 to 1/165, it goes from 2.5/24 to 2.5/165.

Computer software waits a lot more than it did in 1977. That's why 240hz displays feel much more snappier even if it's supposed to be less noticeable -- you're waiting for same 3 frames, but they pass by much faster.

Re:Computer input latency from 1977-2017 (2017) by Jonnax on Thursday December 03, 2020 @11:49AM (#25290933)
I guess so, the difference between 8ms vs 16ms is not much for 1 frame.

Though in my totally subjective experience it feels better.

Interestingly the person who did this latency test also did a keyboard latency test:

https://danluu.com/keyboard-latency/

Compared to the slowest keyboard measured it's possible to shave 45ms which if you were latency sensitive would be the biggest reduction.

Re:Computer input latency from 1977-2017 (2017) by dsissitka on Thursday December 03, 2020 @03:47PM (#25294607)
> A major source of latency is key travel time. It’s not a coincidence that the quickest keyboard measured also has the shortest key travel distance by a large margin. ... Note that, unlike the other measurement I was able to find online, this measurement was from the start of the keypress instead of the switch activation.

That's disappointing. He isn't measuring latency nearly as much as he's measuring point of actuation.

Re:Computer input latency from 1977-2017 (2017) by ClumsyPilot on Thursday December 03, 2020 @09:14PM (#25298151)
Well, thats a reasonable point of reference: for a user, his starting point is clicking the button, the rest is not under his control
Re:Computer input latency from 1977-2017 (2017) by dsissitka on Friday December 04, 2020 @01:22AM (#25299599)
I don't think it is.

With a clicky switch I expect it to actuate when I hear it. With a tactile switch I expect it to actuate when I feel it. With a linear switch it depends on the switch. You can get linear switches that actuate as soon as you'd like.

The more I think about this the more useless it seems. Several of the keyboards he tested come with your choice of switch, different switches with different actuation points, and so you can't just say Keyboard X has a latency of Y without mentioning what switch you were using if you're going to measure from the beginning of the keypress.

Re:Computer input latency from 1977-2017 (2017) by fomine3 on Friday December 04, 2020 @01:05AM (#25299508)
Personally I don't think start clicking as click action is done. If I want to minimumize the gap, I'll use speed switches or thin keyboards.
Re:Computer input latency from 1977-2017 (2017) by gameswithgo on Thursday December 03, 2020 @12:11PM (#25291310)
yes, shaving ~8ms
Re:Computer input latency from 1977-2017 (2017) by bonoboTP on Thursday December 03, 2020 @01:02PM (#25292146)
And on the other side: I very much notice the difference between a corded mouse and a Bluetooth mouse (not a cheap one). It's not unusable, but frustrating enough that I prefer the corded ones. And I'm not a gamer, just doing office stuff, browsing and programming.
Re:Computer input latency from 1977-2017 (2017) by ClumsyPilot on Thursday December 03, 2020 @09:18PM (#25298177)
I have tried like 5 Bluetooth mice, since BL4.0 the latency has improved from 'terrible' to 'tolerable'. It might be something to do with the windows bluetooth stack, as i noticed the respobce was more sluggish during high CPU use, while USB mice seem unaffected.

The same logitech mouse performs much faster through their universal wireless adapter than trhough bluetooth (it has 2 modes), they also have lightspeed adapter, but I haven't noticed much difference.

Re:Computer input latency from 1977-2017 (2017) by tuatoru on Thursday December 03, 2020 @02:06PM (#25293051)
If you haven't already, get a high refresh rate monitor and a 1000 reports/sec "gaming" mouse. The Razer Viper Mini is light, which adds to the feeling of responsiveness. I've bought a couple for other people and they love them.

I recently got a 165 Hz monitor for my decade-old PC (Sandy Bridge era) and with my (now old) G302 mouse, it's like having a new, much faster PC.

Re:Computer input latency from 1977-2017 (2017) by ragnese on Thursday December 03, 2020 @03:56PM (#25294785)
Wireless devices are still hit-or-miss for me. I've also found that my wireless keyboard and mouse actually perform worse if I have WiFi enabled. -_-
Re:Computer input latency from 1977-2017 (2017) by cozzyd on Thursday December 03, 2020 @04:54PM (#25295698)
Are you using 2.4 GHz wifi?
Re:Computer input latency from 1977-2017 (2017) by ragnese on Friday December 04, 2020 @09:23AM (#25302461)
Yes. This is at my office, so I'm assuming there's good reason for 2.4 GHz. Maybe just range?
Re:Computer input latency from 1977-2017 (2017) by cozzyd on Friday December 04, 2020 @10:51AM (#25303643)
Bluetooth is pretty close in frequency to 2.4 GHz wifi, so could imagine some interference there!
Re:Computer input latency from 1977-2017 (2017) by corytheboyd on Thursday December 03, 2020 @12:17PM (#25291414)
Maybe there is something there about IDE hints and whatnot too rendering faster, but those are usually bottlenecked by some async background work (language servers, linters, etc.) anyway which would negate the benefit of the screen refresh rate being faster
Re:Computer input latency from 1977-2017 (2017) by randogogogo on Thursday December 03, 2020 @01:19PM (#25292394)
This is also can be enhanced by tweaking up your mouse sample rates and whatnot. I used to do a lot of setting PS/2 mouse sample rates at 80Hz or more in late 90s that made Windows machines feel almost as nice to use as a Mac.
Re:Computer input latency from 1977-2017 (2017) by 0-_-0 on Thursday December 03, 2020 @01:54PM (#25292887)
Isn't PS/2 interrupt based, therefore instantaneous? I think USB has 125 Hz polling rate by default which can be increased to 1000 Hz.
Re:Computer input latency from 1977-2017 (2017) by tuatoru on Thursday December 03, 2020 @02:32PM (#25293449)
From Wikipedia: -

> The interface has two main signal lines, Data and Clock. ... To transmit a byte, the device simply outputs a serial frame of data (including 8 bits of data and a parity bit) on the Data line serially as it toggles the Clock line once for each bit.

Increasing the clock rate absolutely does reduce latency on a PS/2 port.

1. https://en.wikipedia.org/wiki/PS/2_port

Re:Computer input latency from 1977-2017 (2017) by m45t3r on Thursday December 03, 2020 @12:18PM (#25291426)
Yeah, this is my favorite gimmick of my Samsung Galaxy S20. 120Hz display+240Hz touch sensor makes everything feels so fast and responsive, this is the first Android device that feels faster than my iPad.
Re:Computer input latency from 1977-2017 (2017) by andai on Thursday December 03, 2020 @12:24PM (#25291526)
Does a 240hz sensor help when the display responds at half that rate?

I guess it's because the latencies stack on top of each other?

Re:Computer input latency from 1977-2017 (2017) by kllrnohj on Thursday December 03, 2020 @01:31PM (#25292567)
It's quite common for the touch panel to run at 2x the display refresh rate. Eg, 120hz touch panels have been quite common for years on phones despite the 60hz disply.

It helps both slightly with latency directly, but it also gives you more points to sample from for input prediction which then helps with latency even more. Or for things like drawing applications it'll give you smoother curves assuming the drawing app looks at all intermediate touch samples.

Re:Computer input latency from 1977-2017 (2017) by setpatchaddress on Thursday December 03, 2020 @01:07PM (#25292218)
out of curiosity, which iPad?
Re:Computer input latency from 1977-2017 (2017) by m45t3r on Saturday December 05, 2020 @09:25PM (#25320470)
It on iPad 6. I think if I had an iPad Pro (that also has a 120Hz screen I think?) it would be the same.
Re:Computer input latency from 1977-2017 (2017) by api on Thursday December 03, 2020 @12:04PM (#25291176)
Some recent PC/laptop displays can do 100hz and I even feel a difference between that and the long-standard 60hz. It's a small effect but it's noticeable and it looks a bit smoother and better.
Re:Computer input latency from 1977-2017 (2017) by westwing on Thursday December 03, 2020 @12:06PM (#25291210)
Scrolling, yes. Mouse, absolutely. Typing? Not really. I have tested this side-by-side.
Re:Computer input latency from 1977-2017 (2017) by gameswithgo on Thursday December 03, 2020 @12:11PM (#25291305)
You may not notice, that doesn't mean nobody does. Also it can depend on your operating system. Windows 10 (maybe everything now?) forces you to be in vsync, so increasing refresh rate has a non trivial improvement on the # of ms for a keypress response.

Now whether you will notice that can depend what environment you are in. If your editor already has an input latency of 100ms then shaving 8 off probably is not noticeable. But going from 20 to 12 might be.

Re:Computer input latency from 1977-2017 (2017) by folmar on Thursday December 03, 2020 @05:36PM (#25296237)
Definitely not everything. Non-compositing window managers on Linux (non-wayland of course) work in the old way.
Re:Computer input latency from 1977-2017 (2017) by westwing on Thursday December 03, 2020 @12:42PM (#25291809)
On Windows 10, and I have tested various text input boxes. There's no way latency is anywhere near 100ms, I would notice that.

Generally, from the tests I've seen, input latency is 30-40ms on a wired keyboard on Windows.

Re:Computer input latency from 1977-2017 (2017) by VRay on Thursday December 03, 2020 @04:47PM (#25295598)
you can just point a phone camera at the keyboard and screen, record a video clip, blow it up into stills with ffmpeg, and then count frames

Even at 60fps, you should be able to see the difference between 30ms and 100ms. Newer phone cameras often have a "slow motion" mode that'll give you 120+ fps video, too

SOME people can see the difference between 30ms and 100ms, but it's almost impossible to actually see it. You'll mostly end up feeling that everything sucks and not knowing how or why.

Re:Computer input latency from 1977-2017 (2017) by 867-5309 on Thursday December 03, 2020 @02:57PM (#25293839)
the rate of persistence of the human eye is around 25Hz, hence PAL and NTSC framerates. the upper bound for those hypersensitive is around 50Hz, hence the later generation monitors. anything above this is nothing more than marketing hype. it seeming smoother is merely a placebo to justify the extra cost
Re:Computer input latency from 1977-2017 (2017) by HideousKojima on Thursday December 03, 2020 @03:38PM (#25294454)
Countless blind tests have shown a noticeable difference up to refresh rates over 100hz (and potentially greater). This is the first of many examples that I found: https://techreport.com/news/25051/blind-test-suggests-gamers...

"The human eye can't tell the difference past 30 FPS" was literally just a thought-killing cliche repeated by console gamers getting into internet slapfights with PC gamers.

You can see the difference for yourself here on any 60hz monitor: http://www.30vs60fps.com/

Re:Computer input latency from 1977-2017 (2017) by psykotic on Friday December 04, 2020 @02:31AM (#25299920)
While the difference is noticeable in that 30 vs 60 Hz example, high-contrast foreground/background scrolling is an even starker example: https://www.testufo.com/framerates-text. Just be warned high contrast examples like that can have confounding factors on some displays due to ghosting.
Re:Computer input latency from 1977-2017 (2017) by magicalhippo on Thursday December 03, 2020 @04:46PM (#25295578)
Corridor Crew did a fun and interesting video[1] on how good the eye is.

In it, they have a segment on frame rate[2], where he mentions that the neurons can only fire about every 13ms, or about 75 FPS. But, the important point, they're not in sync like a computer screen is. This means the effective update rate for a group of neurons can be much less.

[1]: https://youtu.be/sPpAXMH5Upo

[2]: https://youtu.be/sPpAXMH5Upo?t=252

Re:Computer input latency from 1977-2017 (2017) by outworlder on Thursday December 03, 2020 @03:08PM (#25293998)
This is not correct. Let's not dispute and go with your claim of 25Hz.

Even then, the problem is that eyes don't work like cameras or monitors. Our eyes don't work with "frames". Each receptor updates on its own time. It's easy to see that, if the updates are staggered, multiple sensors could perceive higher frame-rates, even if they can't individually.

However, there's another angle to this. Disregarding input lag, which is a very real phenomenon and is greatly shortened by higher refresh, higher refresh rate monitors are able to show more 'discrete' steps for anything that's in motion. Our eyes (and brains) perceive this as movement 'smoothness', even if they can't quite make out every single frame that's displayed.

You should try that yourself. Do a blind test.

Re:Computer input latency from 1977-2017 (2017) by yathern on Thursday December 03, 2020 @03:10PM (#25294039)
This is very incorrect. With video, every person can tell the difference between 30hz and 60hz, if they at least know what to look for.

The easiest way to show this is by wiggling your mouse around quickly on a computer screen.

At 30hz - you'll see the mouse teleporting around - hopping from spot to spot, but not moving. For example, if you stare in the middle, and jerk the mouse quickly to the right, you'll see the 4 or 5 spots where it rendered.

With 60hz, you'll see the 9 or 10 spots - and have a stronger illusion of movement.

With 120hz, it might even look as smooth as a real object flying across your screen.

Re:Computer input latency from 1977-2017 (2017) by cgriswald on Thursday December 03, 2020 @03:16PM (#25294126)
I'm wondering if this is why I find 120hz so jarring. It's almost as if I can't perceive the 'hopping' consciously, but I can subconsciously. It feels like my brain is asking "Wait, how did you get over there?" where "over there" is a fraction of a millimeter. I think maybe there is an uncanny valley for motion.
Re:Computer input latency from 1977-2017 (2017) by Jonnax on Thursday December 03, 2020 @04:54PM (#25295704)
Sorry you're wrong.

It's as absurd as saying it's impossible to tell the difference between a 55" 720p display compared to a 4k one at a distance of 1 foot away.

Re:Computer input latency from 1977-2017 (2017) by sirsar on Thursday December 03, 2020 @02:59PM (#25293878)
Are you claiming humans would fail an ABX test between a 60Hz and a 120Hz monitor? That sounds like a pretty extraordinary claim.
Re:Computer input latency from 1977-2017 (2017) by genericone on Thursday December 03, 2020 @03:07PM (#25293984)
So does it seem smoother or does it not? I definitely notice the difference with 60fps video and 120Hz+ monitors.

Additionally, another thing I've noticed in the last decade is the very badly PWM-frequency-tuned LED headlights on some cars. Those engineers selected the wrong LED brightness and tuned it to terrible frequencies which leave flicker-trails when you look at or away from them.

Get those PWM frequencies above 500Hz please! Especially get above 200Hz with your LED frequencies at the very least.

Re:Computer input latency from 1977-2017 (2017) by g3e0 on Friday December 04, 2020 @01:05PM (#25305610)
~25Hz is the _lower bound_ for video* to appear smooth, _as long as there is motion blur_. But user interfaces do not add motion blur to moving objects. A computer monitor at 25Hz would be horrendous to use.

Lower framerates are less noticeable in low light, which is another reason why films look acceptable.

*Talented animators/cartoonists can get away with lower framerates