4K Retina Display

Discussion in 'Mac Accessories' started by slenpree, Mar 13, 2015.

  1. slenpree, Mar 13, 2015
    Last edited: Mar 13, 2015

    slenpree macrumors 6502a

    slenpree

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    Apr 13, 2010
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    #1
    Hi,

    Been searching the web for a 21.5" 4K display. I'd like a display with HiDPI (200+) to use with the 2015 MacBook Pro 13, which supports 4k displays at 60Hz on the thunderbolt 2 ports.

    Can't seem to find one yet, what is everyone else using with their MacBook ? Any 21.5" (or similar sized) 4k displays rumored for release soon ? Be good if apple released one for less than 500 quid!

    Does thunderbolt 2 have the ability to power a smaller external display ?

    Jonny
     
  2. larrysing1963 macrumors regular

    Joined:
    Aug 16, 2014
    #2
    I have been following 4K video on computers for about two years now, and I have never heard of a 4K monitor smaller than 24" EXCEPT for the long-dead IBM T221 and a few recent laptops. Panasonic announced a 20-inch 4K screen at CES a few years ago, but never manufactured it.

    The problem is that text on a 4K monitor that small would be SO very small as to require the user to have probably 20/10 vision and would make it very difficult to work, IMHO.
     
  3. slenpree thread starter macrumors 6502a

    slenpree

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    #3
    thanks for the info, hopefully that will change soon!

    but with regards to text size, what I'm comparing to is how the 5k iMac works - in that the OS treats every square of 4 pixels as 1 pixel before - so the text on a 21.5" 4k monitor is the same size as on a 21.5" 1080p monitor.
    This is just the case of selecting a "HiDPI" resolution in the drop-down menu on OS X.
     
  4. larrysing1963 macrumors regular

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    Aug 16, 2014
    #4
    Well, no regular monitors do that trick. That is a specific trick that Apple does with that computer. Which is why it will not output a 5K signal, and why it cannot be used as an external monitor itself. Dont' expect anyone else to to that anytime soon.
     
  5. slenpree thread starter macrumors 6502a

    slenpree

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    #5
    there is no special trick, it's just a HiDPI option on the list of resolutions. I have tried it with a 2560x1440 monitor, you can set the resolution to "1280x720 HiDPI".

    The only reason the 5k imac cannot be used as a monitor is because thunderbolt 2/DP1.2 does not support 5k (thunderbolt 3/DP1.3 will).
     
  6. larrysing1963, Mar 13, 2015
    Last edited: Mar 13, 2015

    larrysing1963 macrumors regular

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    #6
    You'd think so, but no, they DID use special tricks. It is based on lack of bandwidth, but there are tricks involved. Happy to educate people:

    "To push all those pixels, Apple had to create its own timing controller. A timing controller, or TCON, is what ensures that pixels light up in the right places at the right time.

    Historically, a big bottleneck with displays with this kind of density is bandwidth for the stream itself.

    I've tested a few 4K displays in the past and although those displays look great, most use what's called Multi-Stream Transport (MST) to get the image to appear. MST basically outputs two 2K images (a 1,920 x 1,080 screen) and then combines the two images together. MST works fine, but in some applications, you can sometimes see tearing artifacts.

    Apple's custom TCON gets around this issue by combining two DisplayPort 1.2 streams onto a single chip. This ends up being 40Gbps (gigabits per second) of bandwidth, which is four times that of the previous 27-inch iMac. As a result, there is no tearing on the Retina 5K iMac and no pauses where the display seems "off." It's seamless.

    Apple is also using oxide TFT (thin-film transistor) LCD technology to charge all of those pixels and to make sure they charge faster and last longer. Apple is also using organic passivation — a technique it introduced with the first Retina iPad — to make sure there isn't any pixel cross-talk."
     
  7. slenpree, Mar 13, 2015
    Last edited: Mar 13, 2015

    slenpree thread starter macrumors 6502a

    slenpree

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    #7
    You've got right of track though. When I was talking about text sizes on a 4k or 5k screen and using the 5k iMac as an example, I am referring how 1pts = 4pixel where the non-retina version would be 1pts = 1pixel. The point is - text size is not unreadable as you originally claimed.

    This is the same for a 21.5" 4K display - in HiDPI mode it would have the same text size on OS X as a 21.5" 1080p display. I know it requires MST to do 4k at 60Hz, but it's not a special trick and many non-apple displays support this. P.S. it's not two 2k signals, it would be two 1920x2160 signals.
     
  8. larrysing1963 macrumors regular

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    Aug 16, 2014
    #8
    My point is that if you attempt to read 3840x2160 text on a 21" monitor, it's going to be SUPER small.

    Many users of 24" 4K monitors have the same complaints. So with 21", it would be compounded (smaller, harder to read.)

    Not because of lack of clarity, but because of physical size of the text.
     
  9. slenpree thread starter macrumors 6502a

    slenpree

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    #9
    but I don't understand you're argument, the size of the text is the same as any 21.5" monitor whether it's 2k or 4k, because OS X treats 4 pixels as 1 and uses the extra pixels to improve font smoothing.

    take the 27" non-retina iMac and the 27" retina 5k iMac. They have the same desktop space and text size.
     
  10. venom600 macrumors 6502a

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    Los Angeles, CA
    #10
    He means if you put it in non HiDPI mode and run it at native 4k res, the text will be tiny. 4x as tiny as it would be in HiDPI mode.
     
  11. slenpree thread starter macrumors 6502a

    slenpree

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    #11
    but the topic has always been about HiDPI/retina mode, I have no idea why non-HiDPI/native mode came into it.

    But I think we've definitely established there are no 21.5" 4k monitors out there at the moment :(
     
  12. zhenya macrumors 603

    zhenya

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    Jan 6, 2005
    #12
    Buy the 24" Dell. That's the closest you are going to get, and it does MST.
     
  13. ra004e macrumors regular

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    Jun 8, 2009
    #13
    As far as I know there are no 21.5 4k panels produced yet, hence no monitors.

    Apple could be once to push LG/Samsung for one though as it make most since for 21.5" riMac. 24" 4K panels are ok but retina "best for display" text is to big and 21.5 seems to be best size. As it has been mentioned pixel pitch is not too small as UI would be use scaled ( i.e. iPhone, iPad, Android phones/Tabs, retina macs ) and would would not be very useable @ 1:1 pixel mapping (3840 x 2160).

    Keep an eye on http://www.tftcentral.co.uk as they report new panels in the works ( mentioned 5k panel part before 5k riMac was announced )

    here's the post from Feb 2014 about 5k.
    http://www.tftcentral.co.uk/news_archive/30.htm#lg_panels

    They also have a great panel database.
    http://www.tftcentral.co.uk/articles/panel_parts.htm

    Here's a component sourcing site that lists just about every panel available.
    http://www.panelook.com

    Waiting on 21.5" riMac myself, and would love availability of additional 21.5" 4k displays . I have 5k iMac and 27" is awesome but would rather have smaller size.
     
  14. edanuff macrumors 6502

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    Oct 30, 2008
    #14
    The 24" 4K P2415Q Dell works very well as a retina display. While 21.5" would technically be the ideal size, I don't think any manufacturer is currently making such panels.
     
  15. slenpree thread starter macrumors 6502a

    slenpree

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14 March 13, 2015