Guerdon
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U2711, HDMI, 2560x1440?

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Has anyone been able to display the full native resolution of 2560x1440 via an HDMI connection?

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Moderator
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Re: HDMI to U2711

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HDMI is a video mode and not a graphics mode i.e native resolution. The highest HDMI can go is 1080p which is 1920x1080.

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SkyguyAFFI
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Re: HDMI to U2711

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Though the OLD HDMI 1.0 did only support 1080. HDMI 1.3 supports Deep Color and 2560×1600. So why does U2711 not accept it via the HDMI input?  

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Re: HDMI to U2711

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The U2711 is able to do the following:

12bit internal processing which tested HDMI 1.3 with deep color

I would look to the video card driver or the video card itself as the culprit. Understand, the monitors HDMI is passive. It only does what the video card and video card driver direct it to do.

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SkyguyAFFI
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Re: HDMI to U2711

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Chris,

So you are saying that the U2711 can accept 2560x1440 via a HDMI 1.3 connection?

Regards

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Re: HDMI to U2711

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The revision of HDMI doesn't matter. It should do 2560x1440 for DVI, HDMI, and DP (DisplayPort) IF the video card and video card drivers are capable of transmitting that signal.

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Guerdon
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Re: HDMI to U2711

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Chris,

I contacted Dell technical support before I bought this monitor because although most (but not all) sales people thought that the full native 2560 x 1440 resolution could be displayed over HDMI they were not 100% sure.  Dell technical support reassured me that there would be no problem at all – no caveats or anything!

07/07/2010 – “HDMI is a video mode and not a graphics mode”.

07/07/2010 – “The highest HDMI can go is . . . 1920 x 1080”.

17/06/2011 – “The monitor’s HDMI is passive”.

17/06/2011 – “The revision of HDMI does not matter”.

17/06/2011 – “It should do 2560 x 1440 for . . . HDMI”.

i) HDMI maybe a ‘video mode’ but it is equally capable of transmitting and thus displaying graphics.  Basically, it is just a method of connection.  I appreciate that HDMI is often used for TV / Movies and currently the highest broadcast is 1080p; however, that does not make 1920 x 1080 the maximum possible resolution over HDMI.  Higher resolutions can be and are being captured and will inevitably become more popular in the future.  Furthermore, it appears that the maximum over HDMI is a bandwidth / MHz restriction which is a product of the resolution, refresh rate and color bit depth.  As such, the higher resolutions could potentially be supported by reducing the refresh rate and / or color bit depth to keep within the maximum bandwidth / MHz; as has happened with HDMI 1.4 which supports 4096 x 2160 at 24 Hz for 8, 10 and 12 bits per color channel.

ii) I have encountered multiple people at Dell telling me that the U2711 both can and cannot support the full native 2560 x 1440 resolution over HDMI.  Perhaps everyone can get their story straight once and for all.

iii) Can you 100% guarantee that the monitor’s HDMI port is passive?  Many appear to think that the monitor restricts the input to 1920 x 1080.  Similarly, the monitor’s documentation states “Set the screen resolution to 2560 x 1440 (DVI and DisplayPort) or 2048 x 1152 (VGA) or 1080p (HDMI, Component)”.

iv) As SkyguyAFFI pointed out above, the revision of HDMI does matter.  HDMI 1.0 could not support the monitor’s full resolution or color depth, let alone both.  HDMI 1.3 and above can support up to 340 MHz (10.2 Gbit/s) and the U2711 only requires 241.5 MHz for 2560 x 1440 at 60 Hz & 10 bits per color channel.  However, all the links in the chain must support the desired resolution and color depth (i.e. video card, driver, output, cable, input and monitor).  For example, the cable must be High Speed (Category 2) as Standard (Category 1) cables certified under HDMI 1.3 have only been tested to 74.5 MHz and thus only support 720p and 1080i.  Furthermore, Deep Color support is an optional extra that may or may not be implemented in a specific product.

I am a little confused regarding the advertised “12-bit internal processing” that “enables 1.07 billion colors”.  Surely only 10 bits per color channel are required for 1.07 billion colors (i.e. 2 ^ (10 bits x 3 color channels) = 1.07 billion colors).  Are the color numbers (i.e. 8 or 10 bits per channel, depending upon the output) color managed via 12-bit internal processing to produce more accurate colors?  If so, could the problem be with the system being fooled into thinking 12 bits per color channel are being used and thus limiting the resolution to 1920 x 1080 at 60Hz, which may be the maximum possible for a 36 bit color depth on HDMI 1.3?

In summary, can you absolutely, 100%, confirm that the full native 2560 x 1440 resolution at 60 Hz and 30 & / or 24 bit color (i.e. 10 & / or 8 bits per color channel) is possible on the Dell U2711 over an HDMI to HDMI connection?  Theoretically it is definitely possible; however, have you actually seen it working correctly?

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xgonzalo
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Re: HDMI to U2711

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Guys,

I have the U2711 Monitor and I want to buya 3350 vostro.. Will I be able to use this on 2560x1440 with the laptop hdmi?

Thanks!

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SkyguyAFFI
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Re: HDMI to U2711

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No, absolutely not. 1920 by 1080 is all u can get via the hdmi input on the monitor.
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Guerdon
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Re: HDMI to U2711

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Actually, that is not correct (iro U2711 & HDMI - I have no idea about the capability of a 3350 vostro).

BTW, you should be able to get 2560 x 1440 if the 3350 vostro has a Dual Link DVI or DisplayPort output.  But sticking with HDMI:

The U2711 can display 2560 x 1440 via HDMI IF your graphics card and driver (and cable) can handle it.

You can create a custom resolution or edit the EDID file.

In short, it appears that Dell regards HDMI to be for 'Video' only and as such, considers 1080p (i.e. 1920 x 1080) to be the maximum and thus 'native' resolution for HDMI.

However, HDMI can carry sufficient bandwidth to display higher resolutions.

So, if your video card and driver support it, you can force the monitor (via a custom resolution or by playing with the EDID file) to display the full 2560 x 1440 at 60 Hz and 32 bit.

Note: I am not recommending any 'solution'. You should beware, as officially this is not supported, will probably come with warning from your graphics driver control panel etc. and can cause other complications too.

Dell - Please create a flash update or something that updates the EDID file, so that 2560 x 1440 is seen as a standard, selectable, option.  Alternatively, provide an explanation as to why this does not exist when it is the monitor's real native resolution.