My Adventures with “4K” 2160p and Linux

http://lxer.com/module/newswire/view/200317/

by pmoriarty • 12 years ago

316 138 12 years ago

patcheudor5• 12 years ago

Hats off for trying this in Linux. I gave up on that path a long time ago and am running nine monitors with a Windows 8.1 base OS, utilizing DisplayLink USB docs in combination with the DVI out on my main doc to drive the 2560x1600 30" display (the yellow one) with all others running at 1920x1200 from DisplayLink. I then run Linux in a VM, all from a laptop whith 32GB of ram and three built in SSD's giving me a bit more than 2TB of storage.

Interestingly there appears to be an eight monitor limit total when using DisplayLink for the OS so the ninth monitor is driven from its own DisplayLink doc which I've directly hardware associated with a VM. Of course because the host OS doesn't know about that monitor I also need a second mouse so I can access it. Here's the latest photo of my setup:

http://defaultstore.com/mydesk.jpg

bithush• 12 years ago

Wow. That is a pretty crazy setup. I would worry about neck problems with the position of the top row. How long have you worked with this setup? Also what make/model/spec is the laptop you run it all from?

patcheudor5• 12 years ago

It's taken a few years to build up to this. To mitigate neck pain I:

1) Have set my chair so that it rocks as far back as possible with little force.

2) Sit directly across from the gym and try to visit it twice a day for at least two 15 minute HIIT cardio / body weight workout. I do lots of pull-ups, archers, and have been working up to the iron cross.

3) Only use the upper deck monitors for security reviews where I need "eyes on" resulting actions. I don't use them on a daily basis.

hansjorg• 12 years ago

I guess just using multiple workspaces doesn't work for you?

atrus• 12 years ago

Not when you're trying to monitor a lot of data. Even on my dual monitor setup, One monitor has 4 terminal windows for informational purposes. It would take longer to move to another workspace than to just simply take a quick glance to the left.

dustin9994• 12 years ago

Honest question, do you feel a little ridiculous with that setup? I'm a coder and have 2x24" monitors, and found that to be borderline ridiculous with neck strain, thus the reason I'm going 27". But unless you're running security at a place of business or something with 50 security cams, I can't imagine what you're doing that requires a wall of monitors?

patcheudor5• 12 years ago

Our philosophy in the office is that alt-tab is for suckers. While my setup is the most over the top we have three other people with five monitors or more. We are all security researchers and find the configuration saves a bunch of time in reviews. As an example, I can associate a MitM proxy like the Burpsuite or Fiddler 2 with the server side application which might communicate to web clients as well as to additional web services behind the scenes. That takes up one monitor, typically the one at the far top left. Under that monitor I can then associate another MitM proxy with the client. I can then run the client from my laptop display. If I'm working on a fat client, on the 30" I'll then run Wireshark which will effectively be watching the client. On another monitor I can run sysinternal tools. What remains I use for writing code necessary for the review, running additional tools like Metasploit, e-mail, chat, and research. I arrange my workspace for the task at hand. On a daily basis do I use all nine? No.

Interestingly enough, with this sort of setup it's pretty easy to visually see what's happening when going after an application. Before going to the monitor extreme I'd constantly alt-tab between my monitoring & exploit tools with every action. Now I can run an action and see the results within one workspace. Of course there is a massive downside. It makes competing in CTFs a pain in the butt as I can't drag that setup with me to physical events.

brador• 12 years ago

If you're getting neck strain from using 2 monitors try moving them further away. Ideally you want both screens in your front facing FOV, with only your eyes doing the moving.

zanny3• 12 years ago

I just got my fourth monitor. Two of them are old shitty 900p screens though. My main displays are my new 144hz 24" 1080p panel ($160 black friday sale) a 21.5" 1080p panel over hdmi, and the two shitty old panels I got from clients throwing out their old screens.

Usually the layout is IDE on the main window, docs on the second screen, IRC, git, and github on the third / fourth.

beefsack• 12 years ago

I can't go back from three monitors (currently running 24" displays):

  Left     Portrait, Terminator with two horizontal splits
  Centre   Landscape, Vim with a vertical split, usually have NERDTree open
  Right    Portrait or landscape, browser and/or documentation

I find if I don't have all of those constantly open I can miss stuff, and having them all squished onto a single monitor means I'm not able to display enough information to cover my needs.

colechristensen• 12 years ago

Back in the day, I was much happier with two 4:3/5:4 monitors than I am with two 16:9 monitors, as you say the neck strain... or wasted space is a bit ridiculous. I prefer two squarish monitors to 2x widescreens _or_ giant screens.

aschampion• 12 years ago

No need for a second mouse: http://synergy-project.org/

bane2• 12 years ago

Synergy is amazing. It's hard to explain to people, but as soon as they get somebody to set it up you can watch their faces the first time they move their mouse over to another machine and they go "oh"..."ooOOOHHH" and the light clicks on.

They've recently moved to a paid model, but some older free versions are still around.

I don't know why it's not better known.

rcarmo• 12 years ago

Also Teleport for Mac: http://www.abyssoft.com/software/teleport/ (requires a little tweaking to work with Yosemite)

girvo• 12 years ago

Hehehe. I once worked in an agency, where I commandeered three iMacs, and used Synergy (it may have been a similar application mind you) to use them as "monitors". Each iMac was for a different purpose :P

utku_karatas2• 12 years ago

Aaaand this is why I switched to first a tiling WM, and then to OSX for its intuitive 4 finger swipe workspaces.

Till that switch I was a multi monitor junkie, but after 3 monitors it starts getting bad for your neck, bad for your eyes (with all those monitor backlights burning your retinas) and you also need humongous desk setups.

Nowadays it's just one big monitor and 4 finger swipes.

stinos• 12 years ago

I work both on triple monitor and single monitor+workspace setups and still prefer the triple monitor for a single reason: you cannot put workspaces next to each other and get an overview of multiple windows at the same time.. Just saying it might work for you, but it's by no means a proper replacement for all of us

worklogin• 12 years ago

Truly, if this works for you, then all the best. But we have lots of people at my organization programming, analyzing big data, and troubleshooting operations, and never have I ever heard or seen anyone wish for more than four monitors (two is the standard). I feel the physical issues, the problems with space (if everyone wanted that) and the capital investment all point to the use of workspaces.

This setup makes me think of this, which has been a joke in our circle for some time.

http://www.criticalcommons.org/Members/ccManager/clips/sword...

bryanlarsen6• 12 years ago

If you're looking for a ~40" QHD monitor, you no longer have to buy a TV with its attendant compromises. Check out the Philips BDM4065UC.

pmoriarty3• 12 years ago

How well is it supported on Linux?

jacquesm5• 12 years ago

HDMI 1.4 should drive it at 30 Hz.

bryanlarsen6• 12 years ago

That's a video card question, not a monitor question.

That being said, this monitor supports 60Hz operation in SST with DisplayPort 1.2 so it should work cleaner than those first generation monitors that have to pretend that a QHD monitor is two monitors to work at 60Hz.

ck22• 12 years ago

That's a $1200 monitor !

Has to be something between a $300 sekei @ 30hz and $1200

bryanlarsen6• 12 years ago

That includes VAT, and profiteering on limited supply. Expect the prices to be under $800.

And $800 is a nice compromise between $400 crappy TN panels and $3000 IPS panels. Myself, I prefer VA over IPS because the black levels are so much nicer.

elliotf• 12 years ago

EU-only for now, unfortunately. Not available in the US.

https://twitter.com/PhilipsCare/status/543146398565556225

EDIT: logic inversion

dustin9994• 12 years ago

"The myth I keep hearing is that you must go to larger fonts when scaling up to a 4K monitor. This is not exactly true. Do the math. If you double the screen resolution and at the same time you double the screen width, you have done absolutely nothing to the size of a pixel or the physical size of your fonts."

Yeah but it's a 39" monitor... On your desk! Seriously, I'm all for the largest monitor and resolution and everything else, but there's a point where I'd argue it's just too much. I think a 39" monitor on your desk is crossing that line. I can't imagine the neck strain that's going to occur.

Instead of selling extended warranties, they need to start selling these with chiropractic insurance.

Full disclosure: I just went through several days of research on 1440p vs 4k. I went into it assuming I'd get a 4k monitor, but in the end, opted for the 1440p monitor because I refused to stick a 39" monitor on my desk, and the 28" 4k would require DPI scaling and all that mess.

I'd get a 4k for gaming, assuming I had a rig that could power games at that resolution. Otherwise, I'm happy with my decision to get the Asus PB278Q 1440p monitor.

notjackma• 12 years ago

I can't imagine the neck strain that's going to occur.

I was wondering about this too and the impact on your eyes. For a 39" monitor it's recommended you sit over 5ft away, so the optimal desk environment for such a large monitor will be interesting.

http://www.rtings.com/info/television-size-to-distance-relat...

VLM• 12 years ago

Less, not more.

Too close and the pixels are going to be "big" and too far away and the pixels are going to be invisible.

For example, at 15 feet away the high res would be a waste of money for that screen size, you can't see better than 480 lines at that range.

Extending my arm, I seem to be around 2.5 feet from this screen. Doing the math, higher that 4K at 40 inch screen would be visibly noticeable although its kind of borderline, so 4K should be good enough.

woodchuck64• 12 years ago

Maybe a large monitor should be like a large desk. You only work on what's in front of you but with a glance around you quickly see everything that needs your attention. With a small monitor or small desk, things get stacked and buried, hidden in drawers/folders etc.

pmoriarty3• 12 years ago

A 39" monitor is too big???

I'm impatiently awaiting the day when the norm is high-DPI monitors that seamlessly extend to take up whole walls.. all my walls, to be precise.

Projectors are nice, but the resolution's not there yet. Not to mention the poor color gamuts, poor dynamic range, and typical lack of 3D.

Basically, I won't be satisfied until I get the holodeck... or a neural jack.

39" monitors. psshhh

digi_owl• 12 years ago

Basically, I won't be satisfied until I get the holodeck... or a neural jack.

How about a Rift work space?

https://www.youtube.com/watch?v=db-7J5OaSag

spyder• 12 years ago

"Projectors are nice, but the resolution's not there yet."

You could just use multiple projectors to get higher resolution, but i agree the color and the dynamic range is a problem with projectors.

http://www.scalabledisplay.com/

http://www.matrox.com/graphics/en/products/graphics_cards/m_...

dustin9994• 12 years ago

Yes A 39" monitor is too big for a desktop. If I'm having to move my head all the time while I'm working, that's a no-go for me.

lelandbatey2• 12 years ago

A 39 inch monitor is not nearly as bad as it sounds.

I am currently using 3 1080p monitors in portrait[0], a setup that I like quite a lot. Here are some measurements:

    Width :  39 inches
    Height:  22 inches

    Avg. distance from eyes to monitor:
        22 inches

    Maximum head movement to look left/right edge of monitors:
        40 degrees

    Estimated maximum head movement during use:
        20 degrees

It's a very comfortable setup, and allows for a huge amount of screen real-estate[1]. However, I will say that I use it in a somewhat "different" way compared to other setups. The middle monitor is the main workspace, and is where windows with active work on them go. The left and right monitors hold the 4+ windows with non-active or asynchronous information, like chat windows, documentation, comparison code windows, etc.

[0] http://i.imgur.com/JPY2sum.jpg

[1] http://i.imgur.com/FEumEXi.png

chadzawistowski• 12 years ago

Out of curiosity, what color scheme are you using in Sublime Text?

bryanlarsen6• 12 years ago

I think 40" is exactly right. I've been using a 30" monitor for 8 years now. At first it seemed overly large. Now I want one more column, and find 27" cramped when I have to use one of those.

I am concerned about throwing too much light at my eyes. That's why my next monitor will be one that has solid blacks and good contrast.

I'm not concerned about neck strain. I bet you're more likely to get neck strain holding your neck in the same place for 8 hours than you would

leoc• 12 years ago

In principle at least, there's no reason why having a larger proportion of your field of view covered by the screen ought to make things worse. If fullscreening a document is going to make it uncomfortable to read, well, don't do that then. Now in practise not being able to just fullscreen things can be awkward, but that's a software problem with current OS GUIs, not a hardware issue. https://news.ycombinator.com/item?id=8634121

washadjeffmad3• 12 years ago

I've been using a SE39UY04 under Linux for the past year at about a two foot viewing distance, and it's no strain to use. I'm slightly elevated to its center because I use a stationary bike as my chair, which also allows me to lean in or out as I need. It is pretty big, so I'd probably hate using it if I had to sit in a regular chair all day, too though.

Also, since most major Linux distros handle HiDPI scaling for you out of the box, I only did minor tweaking for text in dconf. Pretty painless overall, physically and literally.

When I game at 1080_120 or 1440_60, I do scoot back a little more out of habit, but it looks amazing close up. I have another 1080_60 TV the same size, and I have to sit across the room if I don't want to see the pixels. If I did get another monitor, it'd be a 22ish inch 1440_144 overclock. They seem pretty much ideal size, refresh, and DPI wise.

to3m2• 12 years ago

DPI would be more of an issue than screen size, I think. I've got 2 portrait (1200x1920) 24" monitors side by side, one in front of me and one to the right: 28" wide, 22" high, for a 35" diagonal. It looks like this: http://quadruple-a.com/2_portrait_monitors.jpg

I find this works well, and isn't too overpowering. A 35"x23" arrangement would surely be no problem in terms of overall size - but you would be squeezing 1.8x as many pixels into rather less than 1.8x the space. Not sure my favourite 6x13 xterm font would look so good any more...

(I also tried adding a 3rd identical monitor on the left (total 42" wide, 22" high, 47" diagonal), and this looked perfectly manageable. So I'd probably be able to handle a 50" monitor... maybe. 3 monitors all lined up was starting to look a bit intimidating. And in the end Linux wouldn't display anything on the 3rd monitor anyway, so what it would actually be like in practice, I couldn't say.)

eeZi• 12 years ago

The real fun starts with high DPI/high resolution displays when you actually have to scale up your desktop environment.

(which works reasonably well nowadays - at least with Gnome!)

kuschku• 12 years ago

Gnome and KDE support it, but sadly there is still a lot of software that doesn’t :/

Rondom• 12 years ago

LWN had a nice article about the challenges of high-dpi displays and how different OSes and DEs deal with them. https://lwn.net/Articles/619784/

kenrikm• 12 years ago

I ran the Seiki 4K as a monitor for about a year. Overall the quality is fine however the 30hz and mouse lag make it less then optimal for anything other then static content. Even scrolling a page is not easy on the eyes.

darshan6• 12 years ago

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.

jacquesm5• 12 years ago

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.

expr-• 12 years ago

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.

pdknsk• 12 years ago

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.

vanderZwan2• 12 years ago

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)

darshan6• 12 years ago

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.

jrockway2• 12 years ago

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.

kevinchen• 12 years ago

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.

darshan6• 12 years ago

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.

bryanlarsen6• 12 years ago

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

jacobolus2• 12 years ago

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.

final• 12 years ago

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

ck22• 12 years ago

How's that 30hz refresh rate working out for you.

Noticed there was no mention of it.

You want to flash the firmware from the 50" version to fix it a little bit but without hdmi 2.0, it is always going to suck.

gwern• 12 years ago

Before starting this project I was wondering how happy I would be with 30Hz updates. Well, at this point I have to say that the display appears solid at that update rate with no noticeable flicker whatsoever. Maybe if I was using this setup to watch sports videos this might be an issue, but for me, I'm finding this 30 Hz update rate to be quite satisfactory for workstation duty.

washadjeffmad3• 12 years ago

To explain this comment, flashing the 39" model to the 50" FW enables true 1080_120 display mode, as opposed to the stock FW's frame doubling.

2160 is limited to 30Hz, but that's hardly an issue for anything but games, most of which are better played in other display modes anyway. Besides, it doesn't make sense that someone who cared enough about hires gaming to buy a GPU beefy enough to run games at >30fps in 4k wouldn't just buy an appropriate monitor as well.

thyselius2• 12 years ago

It's impossible to get used to the mouse pointer in 30hz. I tried hard for weeks but cant stand it.

PSeitz• 12 years ago

I have the same monitor, 4k is cool but the input lag makes it not so efficient to work with. At least I could't get used to.

zaroth• 12 years ago

I have a late-2010 Macbook Air with the nVidia 320M, which can handle 2560x1440 over the mini-DP. I have the Acer B326HUL which was $399 on Black Friday. Seemed like a good compromise since driving 4K would mean a new laptop.

Compared to the 28" 1920x1200 monitor it replaced, I'm very pleased with the 32" 1440p.

nightcracker• 12 years ago

The myth I keep hearing is that you must go to larger fonts when scaling up to a 4K monitor. This is not exactly true. Do the math. If you double the screen resolution and at the same time you double the screen width, you have done absolutely nothing to the size of a pixel or the physical size of your fonts.

What the author seems to be missing here is that if you double your screen size you will likely put the screen at further viewing distance.

ars• 12 years ago

if you double your screen size you will likely put the screen at further viewing distance

So don't.

Why would you anyway?

Todd2• 12 years ago

He makes a point that he uses tiny fonts and that they work for his eyes. The photo of the screen just behind the keyboard is further evidence. I'm guessing it's at the same distance as his previous setup.

Someone• 12 years ago

Even if you don't, pixels near the edge of a flat display will look smaller because they are further away from your eyes.

For example, for a 20 inch diagonal monitor at 10 inches distance, the corner pixels have about 0.7 times the angular extent of those in the center of the screen, or about half the solid angle.

Replace that by a 40" diagonal monitor at 10", and that factor drops to about 1:sqrt(5), or 1:5 in solid angle.

So, I guess you will need larger fonts, _if_ you keep your eyes in the same position on your larger monitor. There probably are publications on this in studies on airplane ergonomics.

undersuit• 12 years ago

If you're running a 2x2 monitor setup do you move it further away from your face? I don't move my 2x1 further away than i would a single monitor.

shmerl3• 12 years ago

KDE will only fully support it in Plasma 5.0. As of now it's somewhat messy and requires lot's of manual tweaks besides changing the DPI.

See https://community.kde.org/KDE/High-dpi_issues

However one should be careful when getting monitors with such huge resolution since they put more requirements on the GPU. For example if you want to play games in native, it will require dual GPU at least which is a very pricey overkill otherwise. Current video cards don't cope with such resolution well yet. That besides the fact that such monitors are very expensive on their own.

Also, ergonomics wise, for me personally 24-27" is a sweep spot. Anything larger than that becomes uncomfortable to use unless you place it in some distance.

RussianCow• 12 years ago

For example if you want to play games in native, it will require dual GPU at least which is a very pricey overkill otherwise. Current video cards don't cope with such resolution well yet.

Can't you just set the games to a lower resolution? Wouldn't that lower the GPU load?

shmerl3• 12 years ago

You can, but for LCD monitors non native resolution usually degrades image quality. And basically it means that for that scenario you aren't using what you paid for. So it's something to consider when buying it.

detrino• 12 years ago

I don't know why this was downvoted, everything you say is true.

zanny3• 12 years ago

Most desktop 4k monitors are being released at 28". That seems reasonable, albeit I do prefer the 24" ones with good DPI. Again, Windows continues to hold us back, because vendors don't want 250+ DPI on the desktop because Windows cannot handle it.

Matthias247• 12 years ago

No, it's not a Windows problem. Actually Windows 8.1 has a pretty reasonable Hidpi support with infinetly adjustable scaling factor. I have my 28" 4k set to 175%, but I could also put it to 300% which would be ok for 250dpi. Overall I get better results than with various linux desktop managers.

Win 8.1 also allows to set the dpi independently for each connected monitor. That's important when you connect a 4k screen to an average notebook or a tablet to a TV.

The main problems are the applications (Steam - I'm looking at you) which were not written to support a higher DPI. Some of them will simply be lineary upscaled by Windows which causes bluriness but at least makes them usable. However other ones will have tiny user interfaces. But with 150dpi they are at least still usable when you have to set them to non-scaling (100%).

I think it will still take some time until the problems are fully resolved. Most developers have no hidpi screens and therefore can't even see the problems they're supposed to fix.

jrockway2• 12 years ago

So all that and it's only refreshing at 30Hz?

Here's my long post about the current state of the art: https://news.ycombinator.com/item?id=8549629

siliconc0w• 12 years ago

I looked into this setup but it gets pretty ridiculous if you want to do any gaming. You want 4k @ 60hz with 4:4:4 color sampling at a reasonable <40" but it soon begins to feel like you're hunting a rare animal. With only hints and whispers strewn throughout a dark abyss of forums threads and amazon reviews. The kind of places where people put AMD driver revisions in their signatures. I don't think we're quite there yet.

marknutter• 12 years ago

Can you get a 4k display and use it at its full resolution for everything but gaming, and then just switch to a lower resolution for gaming when you want the higher refresh rates?

bryanlarsen6• 12 years ago

According to reports, it scales 2560x1440 beautifully. 1920x1080 obviously works well, since that's an integer multiple.

lrizzo2• 12 years ago

I have tried 4K@30Hz using HDMI on five different TVs (not monitors): Seiki 39" US, Seiki 39" UK (US and UK modes are different), Hisense 42K680, Samsung UE40HU6900DX, LG 40UB800 (the latter three are in Italy and seem available across europe).

In all cases the additional display lag wrt my retina MBpro screen (measured with the small HTML/JS at the end) was huge, in the 130-230ms range, i.e. 4-7 frames. As a comparison, even the low end 1080p TVs i tried (at 60Hz) only gave 0-16ms additional lag, i.e. one frame.

The problem is not 30Hz vs 60Hz, but a video pipeline which is too deep, and cannot be shortened in any of the models i tried (even the models that have a "gaming" mode disable that control when running at 4k). Note that even at 30Hz one frame is only 33ms so anything more than 66ms indicates excessive pipeline depth. Based on my measurements, I think that at the moment the chipset that do 4k (upscaler etc.) are still buggy/immature in terms of features, and probably we need to wait the next generationof silicon to get 4K TVs that can be used as monitors.

I have become used to the 130ms lag but it is not pleasant.

Note that the Acer Chromebook C720 ($199) can drive the screen at 4K through the HDMI port. I had no problem with FreeBSD using high end nvidia cards (GT640 and GT750), whereas lower model seem unable to use pixel clocks above 165 MHz (you need about 290 MHz to run at 4k).

<!DOCTYPE html><html><head><script> Object.prototype.d = function(l) { return (this + Math.pow(10,l)).toString().substring(1, l+1) } function g(x) { return document.getElementById(x); } function clock() { var t=new Date(); g('txt').innerHTML=t.getSeconds().d(2)+'.'+t.getMilliseconds().d(3); setTimeout(clock,1); } </script></head> <body onload="clock()"> Set PC to mirror screens, take a snapshot with a camera, compare times<br/> <div id="txt" style="font-size: 120px;"></div> </body></html>

firloop• 12 years ago

    displaylag.html:5 Uncaught SyntaxError: Unexpected token function

    displaylag.html:10 Uncaught ReferenceError: clock is not defined

Wasn't able to run that page you put at the end of your comment on Chrome 39.0.2171.95. Am I missing something? Here's a codepen: http://codepen.io/pen/yyOxXQ

sumnulu• 12 years ago

Fixed: http://codepen.io/anon/pen/GgZXYO

Zardoz84• 12 years ago

"I can send an IP packet to Europe faster than I can send a pixel to the screen. How f’d up is that?" - John Carmack

https://twitter.com/id_aa_carmack/status/193480622533120001

dedward• 12 years ago

I don't mean to be "that guy"... because this is, of course, about linux running 4k.

But much of the discussion seems to be around what the point is, whether it's useful, and so on.

As someone who's been using one of the new 5k iMacs since it came out (so that's 5120x2880 in a 26" display)... let me add a bit, hopefully without sounding like an apple fanboy.

First - running it at actual 5k, rather than at 3200 or 2560 HiDPI, is crystal clear, amazingly sharp, but too small at this size. With a 40" display it would be perfect, I imagine. At full 5k, you can fit an amazing amount of stuff on a single screen, and it's handy for certain short troubleshooting sessions - but stuff can be so small it's straining. The stuff is still crisp though, if you can manage to focus on it. The detail is there. 12 point fonts are barely readable to my 40 year old eyes unless I get closer.

3k is just fine, and 2k is what you'd expect - but both are using HiDPI rendering and you get stunningly crisp fonts and detailed images and whatnot.

I wouldn't trade it for anything, even if I don't run in 5k all day long.

lrizzo2• 12 years ago

Speaking of screen size, having used it i confirm that 39-40" is what i find the minimum acceptable size for 4K if you are not running in HiDPI mode. It corresponds to 1080p at 20" which (which to my 50y eyes is almost below the threshold of what i can see).

miduil• 12 years ago

I wonder if a bigger screen will make that difference for me. I've been using an 1920x1200 24" screen and that was nice, but for the past 12 months I've been fine with my 1366x768 12.4" laptop. Tough, I'm using a tiling window manager which makes a difference compared to others I guess.

vostrocity• 12 years ago

No one has mentioned that the author of the piece likes to leave his monitors on 24/7. I often see many monitors in offices left on overnight running a screensaver. Is there a good reason for this, or simply ignorance?

netforay• 12 years ago

Can some one tell me why it has to be 30Hz vs 60Hz. Why it can not be 40Hz or 50Hz?

My Adventures with “4K” 2160p and Linux

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