[K12OSN] X starts, but turns off before GDM

Angus Carr acarr at saskforestcentre.ca
Tue May 30 17:57:39 UTC 2006


Rob Owens wrote:
> --- Angus Carr <acarr at saskforestcentre.ca> wrote:
>
>   
>> <Clip...>
>>     
>>>> All my clients are RIVA 128. I bet you are trying
>>>>         
>> to
>>     
>>>> run them at 16
>>>> bit color. Xorg or Xfree86 don't support 16 bit
>>>> color for this card. I
>>>> have to run them at 24 bit color in lts.conf.
>>>>
>>>>     
>>>>         
>>> I fixed my problem with XSERVER = vesa, but I'd
>>>       
>> still
>>     
>>> like to know how you deal with these video cards. 
>>>       
>> I
>>     
>>> seem to recall an error message at one point about
>>> "depth 16".  How do I stop it from trying to run
>>>       
>> at 16
>>     
>>> bit color?  Do you use XSERVER = vesa, or XSERVER
>>>       
>> =
>>     
>>> auto?  Do you need a special mode line?  I don't
>>>       
>> fully
>>     
>>> understand the mode lines...
>>>
>>> Thanks
>>>
>>> -Rob
>>>   
>>>       
>> Google for "X_COLOR_DEPTH", which is a parameter in
>> lts.conf. That's 
>> about all you need to set, either globally or by
>> station.
>>
>>  From
>>
>>     
> http://www.ltsp.org/documentation/lts_ig_v2.3/lts_ig_v2.3-9.html:
>   
>> *X_COLOR_DEPTH*
>>
>>     This is the number of bits to use for the color
>> depth. Possible
>>     values are *8*, *15*, *16*, *24* and *32*. 8
>> bits will give 256
>>     colors, 16 will give 65536 colors, 24 will give
>> 16 million colors
>>     and 32 bits will give 4.2 billion colors! Not
>> all X servers support
>>     all of these values. The default value for this
>> is *16*
>>     
>
> Thanks, that took care of it.  But now I've got
> another question.  What is the down side of using the
> vesa driver.  The reason I ask is because keeping
> XSERVER=auto, and setting X_COLOR_DEPTH=15 gives me
> worse looking graphics than XSERVER=vesa and leaving
> X_COLOR_DEPTH alone.  Is vesa bad at motion?
>
>   

My experience with vesa modes is that they are less accelerated, as they 
are designed for broad compatibility. There is some acceleration, but 
not for motion video.
By default (on i810 machines, anyway) I get an awful-looking desktop 
with vesa, but 16-bit 1024x768 on the i810 driver (or auto).
I suggest you try X_COLOR_DEPTH=24, given that the card you have won't 
do 16 bit. It sounds like it is going to 8bit colour, which is only 
vaguely describable as colour... :-)
The VESA driver will work, but the riva driver will work better. The 
riva driver should do all the 2D acceleration the vesa driver will do 
and more- 3D, movies, performance.

Angus.




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