[SUCCESS] 2560x1440 support on new VPC-Z2 (Dell U2711)

[psyq321]

I managed to get the 2560x1440 resolution to work on my new VPC-Z2 - via HDMI output (no PMD, built-in Intel HD 3000). You only need a good HDMI->DVI cable (or an adapter, I haven't tested that). This is needed because HDMI input of U2711 appears to be limited to 1080p - so you need to plug your Z HDMI output in the DVI input of the U2711.

It is limited to 35 Hz, though (as it is using single-link bandwidth) - but it is working nevertheless! And it looks quite stunning, I'd say

Intel's own "custom resolution" tool in the graphics control panel is refusing to accept needed values so this needs a bit more manual work :-)

Below you will find steps needed to get this to work. Please note that those steps are related to Dell's U2711 monitor only!!! DTD data can be monitor specific and if you have a different monitor you will need to calculate monitor-specific DTD data. All this is on your risk, as fiddling with display timings can be dangerous for your monitors!

You need the following:

- DTD Calculator: Custom Resolution Tool for Intel Graphics: Easier Overscan Correction - AVS Forum

With this tool, you can enter the EDID/DTD data and also change it. It has a nice "Registry Hack" option allowing to directly upload the DTD timings so Intel's driver can use them.

So, for DELL U2711 MONITOR SPECIFIC!!!! FOR OTHERS YOU WILL HAVE TO GET THE RIGHT DTD VALUES AS THESE WON'T WORK! -

- DTD data is available from here : http://forums.whirlpool.net.au/archive/1479962 (provided by user: dkh)

I am also including it here so you can directly paste it in DTD tool:

00FFFFFFFFFFFF0010AC56A04C5245300B150103803C2278EA8E05AD4F33B0260D5054A54B008100B300714FA9408180010101010101023A0018A1A02D50582C250055502100001E000000FF004A343132543133393045524C0A000000FC0044454C4C2055323731310A2020000000FD00384C1E5111000A20202020202001C0

- Paste these values in the DTD Calculator (run it as Admin, by the way) on the "Interpret EDID" page

- Click on "Interpret EDID" button - you should get the 2560x1440 resolution values on the left

- Go to "Registry Hack" page, add a new DTD field, and type "Get Calculated". After it is added, you will be asked to reboot your computer

- After reboot, you should be able to select 2560x1440 resolution - enjoy your new stunning view

If it does not work - doublecheck that the DTD data is actually added to registry - if "No of DTDs" is 0 or "DTD 1" shows bunch of zeros, it means that the data was not saved - repeat the "interpret edid" step, and then go to "Registry Hack" and just click "Get Calculated".

[Qwaarjet]

otherwise it's limited to 1080p or 1920x1200? Nice work yet again Psyq

[ComputerCowboy]

Did you use a straight HDMI cable? I was under the impression that the U2711 would max out at WUXGA on the HDMI input.

[psyq321]

Actually, I forgot to mention - I was using HDMI->DVI adapter, thanks ComputerCowboy for noticing... then, the DVI part is just plugged in in the regular DVI input of the U2711 monitor.

The cable itself is just ordinary HDMI->DVI, it is just high quality (and it says HDMI-Dual Link DVI adapter on its box which is bull... as it is impossible to do that without additional circuitry).

[Generic User #2]

how is the screen when the refresh rate is that low?

[ComputerCowboy]

It should be fine. I use some HDTV's with 24P with the Z sometimes since 60Hz can flicker sometimes (haven't figured out why) At any rate 24P is usable for office apps and web surfing. 35Hz should be much better. It is a progressive resolution so it is not like you are gonna see scanlines.

[psyq321]

Quite good for "normal" work actually.

But this is expected, as we are talking about digital "refresh rate" which is merely a minimal interval for change of the display content, unlike in CRT era where refresh rate was also connected to actual displaying of the pixels and lower refresh rates implied flickering as pixels faded out due to physics of the displaying process in CRT monitors.

The only area where I expect some issues is video playback - some judder is inevitable as there is a mismatch between video frame rate and display frame rate but, then again, we in Europe have this issue with any type of PAL content (25 Hz) on 60 Hz display

Same goes for 24p BD content - unless you force the monitor to 24 Hz / 48 Hz / 120 Hz you will also get some degree of judder - and I suspect most people are just keeping 60 Hz refresh rate for all uses.

[ComputerCowboy]

Many high end displays will tak 50Hz also which should fix PAL issues. The BRAVIA HDTV I just got rid of, when I got the U3011, took 50Hz over HDMI.

35Hz would make for some really interesting judder. At least with standard mismatched refresh rates you have 3:2 pulldown. How does the computer handle the framerate when you are talking about 35Hz. Does the player handle it? I would think maybe the driver does. Where does the conversion happen?

[psyq321]

Well, I guess there is just no conversion anywhere...

- Your media player will happily continue to deliver frames at the original content frame-rate (say, 24 Hz in case of Blu-ray, or 50/60 Hz in case of PAL/NTSC content)

- Video decoder in the graphics card will perform the necessary decoding / deinterlacing in the native content frame rate, again...

- Display controller in the graphics card, however, will pull data and send it to the output in the target frame rate - 35 Hz in this case.

So, there will certainly be some judder - because the "frame consuming" and "frame producing" processes operate at the different rate - the end result is that some original frames will be "dropped" (missed by the display controller).

To deal with this in a better way, there would need to be a FPS conversion involving actual changing of the content, interpolation, etc... and As far as I know, display controller hardware in any consumer graphic card would just not do this for 35 Hz - at most, they have typical deinterlacing pulldown detection and some deinterlacing algos, but custom FPS conversion - this is certainly not in the feature list

[ComputerCowboy]

wouldn't it be more like uneven frame doubling? as long as the content is 24P?