Comment by darshan | Hacker News Reader

Comment by darshan | Hacker News Reader

I've been running 3840x2160 on the 23.8" Dell UP2414Q for the past month, and I couldn't be more pleased. Well, I could if I had it running at 60 Hz rather than 30 Hz, but having twice the PPI is worth the cut in the frame rate to me without question. I'm using the open source Intel drivers and the on-die GPU of my i7-4770K, and everything works out of the box at 30 Hz. Patches to get things at 60 Hz are in the works, but it's pretty complicated because the software needs to treat the display as two separate 1920x2160 displays due to limitations in the DisplayPort spec.

My desktop is where I spend the most time, yet it was the last remaining device I use where there were visible, ugly, distracting pixels everywhere. Now I never see pixels in my daily life, and reading and writing on my desktop have become significantly more pleasant. I highly recommend switching to a high-DPI monitor for anyone who spends much time on the computer (which is probably almost everyone here).

Oh, most software works just fine once I manually set the DPI in KDE's system settings. Upgrading to Plasma 5, the only software I use that isn't scaled properly is Chrome. Apparently they're working on it, but I only use Chrome for Netflix, and it's not too bad having tiny browser tabs for that one use.

> Now I never see pixels in my daily life

Just wait for a bit and that problem will solve itself handily. And then you'll be wishing for the time when you could see pixels.

Having a poorer eyesight is not going to make fonts comprised of ten or so square pixels (in a direction) a bigger joy to read. Reading off a low DPI display is not only slower, but it also tires out your eyes faster.

Ah, but having a 30+" screen a few feet from your face and upping the font size in fact does help. It's all about the distance, not about the number of pixels or the font size.

So the ideal (for me) is a large high res monitor sitting 3 or more feet away from me. The first hint you're on this path is when your arms start to be too short for reading books and when you are 100% sure that the gray squiggles on that chip used to have meaning.

Even before eyesight problems, it's recommended to have a screen at least at 65cm to avoid forcing eyes to accomodate, which is more or less our arm's length. iPhones are a pleague for eyesight, tablets are slightly better (except that we read them longer) and a huge screen, far away in the distance of the desktop is certainly a good solution.

The optimal viewing distance for reading is called the Harmon Distance. It's normally the distance from your knuckles to your elbow. Of course, vision problems and aging can require adjustments, but that's a good starting place.

> The optimal viewing distance for reading is called the Harmon Distance.

I’m not an expert here (I had to look up the Harmon Distance), but from what I understand from other reading about eye strain, this should be rephrased as:

“Reading gets less comfortable if the material is any closer than the Harmon Distance, with some variation depending on age and individual differences between people.”

In particular, there are two factors that make focusing at close distance uncomfortable: (1) you need to flex the ciliary muscles to focus the lens (this is called “accommodation”), and (2) you need to flex the medial rectus muscles to rotate the eyes inward to point at the same spot (this is called “convergence”).

Both sets of muscles start getting strained if you look at a very close object for a long time with no breaks.

Looking at further away objects, even all the way out to the horizon, isn’t really a problem though.

I think a large screen with large text at a greater distance is far more comfortable. Is there a good source for any reason why closer would be better?

Interesting. I've been playing a bit with the Oculus Rift DK2, and if I understand things correctly[1], if/when they up the resolution one more "level" beyond the DK2, it should actually be possible to use for many kinds of work. UI design people will need to realize that mile-high letters on the horizon are better than thin lettering close to the head, first (I'm looking at you, Elite:Dangerous docking bulletin board etc).

[1] http://oculusrift-blog.com/oculus-rift-faq/492/

No anchors in the page, I'm referring to: "Will the Oculus Rift cause eye strain after extended use?

The Oculus Rift causes very little eye strain, particularly compared to other standard displays or headmounts.

Normally, when you take a break from using a monitor or TV, the idea is to give your eyes a chance to focus and converge on a distant plane. This is a natural position of rest for your eyes.

With the Oculus Rift, your eyes are actually focused and converged in the distance at all times. It’s a pretty neat optical feature."

Personally, I wouldn't run at 30Hz if someone paid me for it. And you don't have to either, because 60Hz support for your GPU is available (from kernel 3.17 best I can tell). You may have to enable DP1.2 or MST in your monitor settings to use it.

To be fair, low refresh rates are much more bearable on LCD screens they used to be on CRTs, since there is no flicker.

(This is assuming the task at hand doesn't require a high refresh rate of course - a reflex based game like an FPS would be a no-go)

This, is a really important point. LCDs are NOT CRTs. So it isn't that the top left pixel of the screen is getting dimmer and dimmer while the CRT is painting lower pixels, on an LCD it is simply not changing.

What "30Hz" means in LCD terms is that if you go to change a pixel, the fastest you can do that is once every 33 mS but during the whole time it isn't changed, it stays the same intensity.

Basic desktop usage is unbearable at 30fps. Just dragging windows around you have to insert a deliberate pause to make sure the pointer is really where you want it to be because the screen is updating so slowly. Flicker is not the problem, slow screen updates are.

Can confirm, I am running a UP2414Q @ 30 Hz because my 2013 13" MBPr does not support 4k at 60 Hz and it is pretty bad. I am planning on replacing the laptop soon. Otherwise the screen is great and non-4k 24" screens look terrible to my eyes now.

That is completely different from my experience; I think you must have another problem besides the 30 fps frame rate. Perhaps your machine is just having trouble pushing that many pixels? On my machine, animations are just slightly, subtly choppy -- like Android used to be before all the "butter." But there's still very much the sense of instant responsiveness.

Perhaps you mouse slowly in the first place so it doesn't impact you.

I'm pretty sure I mouse as quickly as anybody. It's just that the difference between 17 ms per frame and 33 ms per frame on my system only affects the smoothness of animations. There's no perceptible lag no matter how quickly I move things around.

Right - but when you stop moving the mouse, there's now an extra 17ms before you see the result. I assume that's his/her point.

Maybe this wouldn't bother me any more personally, but I bet I would have noticed it when I was 23!

To add one more data point, I usually set my mouse sensitivity to maximum (people usually complain about how sensitive my mouse is when they borrow my computer), and while 30fps is fine for everything else, it's unbearable to me when mousing.

I just did a test: Over 5 seconds I moved my mouse to the top of my monitor and back down 15 times, which works out to 12000 pixels per second, or 396 pixels per frame - which seems about right for how far the mouse seems to jump per frame. For comparison, Chrome's Close Tab button is 15x15 pixels, and HN's upvote button is 8x7 pixels. Framerate really is the limiting factor for how long it takes me to move my mouse onto the kinds of click targets common in computers.

Another test: it takes around 6 seconds to close 7 tabs with a mouse in Chrome in 30fps, and 4 seconds to close the tabs in Chrome in 60fps.

So I think I've pinpointed the exact problem. There are two parts to moving a cursor to a click target: quickly moving the cursor in the target's general direction, and then slowly moving to its exact position. Both are much more unpleasant in 30fps.

Quickly moving in the target's general direction: it's a lot easier to track a 10x20 pixel cursor when it's jumping 150 pixels per frame than if it's jumping 300 pixels per frame. (These are my own numbers, judging by people's reactions to my mouse sensitivity settings, it's likely yours would be lower.)

Slowly moving to the target's exact position: if the click target is 8x7 pixels like HN's upvote button, I can't move any faster than 2-3 pixels per frame, which is obviously half as fast in 30fps as in 60fps.

Well, if you mouse that fast then your use-case is similar to the aforementioned twitch-based FPS games.

> There are two parts to moving a cursor to a click target: quickly moving the cursor in the target's general direction, and then slowly moving to its exact position

This is a pretty basic usability issue and one of the reasons we put clickable things on the edge of the screen if we can.

See also:

http://www.joelonsoftware.com/uibook/chapters/fog0000000063....

(note that this is a great example of mouse and touch screens having completely different usability requirements)

I'm certainly not a twitchy mouse user, but I see very visible lag when using a mouse at 30fps and it drives me crazy.

Even scrolling text on a terminal becomes and 'issue' at 30fps. It get's 'blurry' is the closest I could say, Again, it drives me crazy.

Monitors with 40ms of input lag used to be commonplace and regarded as completely usable for non-gaming purposes. The extra input lag on a modern monitor that comes from running at 30Hz instead of 60Hz shouldn't be a huge problem, though depending on how much input lag there is due to other sources it might be at least noticeable.

Yes there is, you just pointed it out. There 16-17 ms of extra lag compared to a typical monitor. When I stop moving my mouse, I have to wait up to 33 before I can see where it actually is. That is easily noticeable. Stick a bunch of people with 30Hz monitors and watch their misclick rate jump.

Dragging windows does not constitute my basic desktop usage. I probably drag or resize a window at most once per day, and I'm not even using a tiling or significantly keyboard-driven window manager, it's just stock OS X.

>Dragging windows does not constitute my basic desktop usage

Fair enough, but it does for most people. The claim I was disagreeing with is that >30fps only matters for action games. It is noticeable for most tasks that use a mouse.

I was able to get 60 Hz by simply enabling DP1.2 on the monitor, but then I had two virtual displays, which was quite annoying. The patches to make the whole stack properly support this sort of monitor are not quite there last I checked (a few weeks ago). Dave Airlie, who's responsible for most of the work on this at all levels (from the kernel through through the window manager) has things mostly working, but it's not ready for prime time. He ended up giving up on doing everything entirely in the kernel as he had originally tried, so now everything up the stack to the window manager needs patching. He has experimental support in GNOME. I may attempt stretching myself and seeing if I can get similar changes into kwin while I'm on winter break, but I've found 30 Hz to be entirely bearable; most of the time I don't even notice.

Is there a way to get 60Hz on a mac you think?

I'm pretty sure I came across information that up-to-date Macs can do all the necessary wrangling to make it work. If I planned to buy one and connect it to a Mac, I'd do some Googling to verify that, though.

In my experience, I can tell whether or not a display is at 30Hz or 60Hz, but it doesn't really affect actually getting things done.

The same could be said for things like color accuracy: it's annoying that it's wrong, but it doesn't really matter for my work.

That said, when it's fixable (and in the author's case it is), you should fix it.

Possibly off topic, but what do you think about the Dell UP2414Q's color? I saw the 32" version in a store and the viewing angle was pretty bad.

I'm not necessarily a good judge of monitor color quality and accuracy, but to my eye, it's fantastic. I'm normally right in front of it, but my partner is off to the side when we watch something on Netflix, and that angle doesn't seem to adversely affect color.

The UP2414Q is IPS, so viewing angles should not be a problem.

I’m really impressed by the Dell UP2414Q. I’d highly recommend it over just about any other external monitor. Color is consistent across the front, and quite accurate. It’s pretty bright with good contrast. And the high resolution is just stunning.

The only computer display I’m more impressed with at the moment is the 5k “retina” iMac display.

You probably saw Dell's 28'' 4K monitor, that uses a TN matrix.

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