solved - Ubuntu 10.04 screen resolutions

marthter marthter-FFYn/CNdgSA at public.gmane.org
Thu Jun 24 21:07:34 UTC 2010


On 10-06-24 01:40 PM, Lennart Sorensen wrote:
> On Thu, Jun 24, 2010 at 10:52:21AM -0400, marthter wrote:
>    
>> Yes and no, and I've tried it both ways with both the open and closed
>> driver.  On the (on board) video card has only VGA output.  The monitor
>> has a VGA input and a five-BNC-connector input (and I have both a
>> VGA-to-VGA cable for the first case, and a VGA-to-5-BNC cable for the
>> second case).  It claims in the manual to support DDC only when using
>> the VGA input but I didn't get any output in Xorg.0.log similar to yours
>> (mentioning DDC or EDID) with either cable.
>>      
> 5 BNC only provides RGB and H/V Sync.  No data.  You need extra pins
> for the DDC data.
>    
Yes, that's what I meant.  I wasn't expecting the DDC to work when using 
the VGA-to-5-BNC cable, but I was expecting it to work (per the 
monitor's manual) when using the VGA-to-VGA cable, yet it didn't.

>> After suffering at low res for a few weeks (a little too busy to
>> tinker), I took another stab at this...
>>
>> The DDC comment was on the right track however.  I tried dozens of times
>> to alter xorg.conf to tell it     HorizSync 30-115  Vertrefresh 50-160
>> in the Monitor section.  Both with and without also specifying a
>> ModeLine for 1920x1440.
>>
>> In the tries where I gave a ModeLine, the log file was saying 'No valid
>> modes for "1920x1440"; removing.' but gave no more info on how this was
>> determined.
>>      
> There may not be any modelines by default for 1920x1440 (what an odd
> resolution).
Yes I was pleasantly surprised to find it in the list one time many 
incarnations ago and have often had to jump through hoops to get it back 
(this old monitor has outlasted many a box).  Though on the other hand 
it isn't really that odd, as it _is_ a 4:3 resolution (640x480 tripled 
in each direction) and for HD viewing (1920x1080) it displays more or 
less natively, i.e. doesn't require scaling, just the black bars.

The one I never understood was 1280x1024 (5:4 aspect when almost 
everything was 4:3 - until the more recent 16:9 trend of course).

>    I guess it is within the range supported by VGA (2048x1536
> is supported as far as I recall, although I don't remember at what
> refresh rate).
>    
>> Eventually I found some post on how to turn up logging in xorg.  I
>> couldn't find where is the "real" place to increase this logging so that
>> it takes effect on a normal startup, but the fudged way I did it was to
>> switch to the text console (Ctrl-Alt-F1), stop gdm with '/etc/init.d/gdm
>> stop', then start X with 'startx -- -logverbose 6'.  This showed (among
>> other things) the following very suspect lines in Xorg.0.log:
>>
>> (II) NVIDIA(0): HorizSync : 28.000-55.000 kHz
>> (II) NVIDIA(0): VertRefresh : 43.000-72.000 Hz
>> (II) NVIDIA(0): (HorizSync from Conservative Defaults)
>> (II) NVIDIA(0): (VertRefresh from Conservative Defaults)
>>
>> This eventually led me to a suggestion to just pick any resolution
>> offered in the NVidia X Server Settings GUI, and to use the button which
>> says "Save to X Configuration File".  This gave me a bigger xorg.conf
>> file where the spot that needed changing was clear:
>>
>>
>> ...
>>
>>
>> (In the above I changed only the HorizSync and VertRefresh lines.)  On
>> next startup, all the resolutions up to 2048x1536 were in the NVidia GUI
>> as expected.  I'm not sure which of the additional options that the GUI
>> added were the relevant ones for getting it to NOT ignore the HorizSync
>> and VertRefresh (which I had already tried eight ways to Sunday).  But
>> anyway it is working now in time for the round of 16 : - )
>>
>> Thanks to all commenters.
>>      
> Neat.  So it all works now then?
>    
Yes, working great and the TV (FIFA football of course) playback is 
smooth now with the NVidia driver, unlike the open un-accerated driver 
(where I initially could get the resolution I wanted but not the 
smoothness).

Although one could argue this is still a bug, as there should be a more 
user friendly option for when the monitor is not detected at all.  I 
guess they went down that road in past releases of letting you choose 
from every brand and model under the sun and are moving to autodetection 
more now.  Shrug.

Cheers.

Martin

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