ati and 2 monitors with 2 different resolutions : is it possible ?

[Alex Deucher]

On Mon, Jan 5, 2009 at 3:51 PM, giggz <giggzounet at gmail.com> wrote:
> Alex Deucher a écrit :
>> On Mon, Jan 5, 2009 at 3:45 PM, giggz <giggzounet at gmail.com> wrote:
>>> Alex Deucher a écrit :
>>>> On Mon, Jan 5, 2009 at 2:53 PM, giggz <giggzounet at gmail.com> wrote:
>>>>> Alex Deucher a écrit :
>>>>>> On Mon, Jan 5, 2009 at 1:42 PM, giggz <giggzounet at gmail.com> wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> Happy new year!
>>>>>>>
>>>>>>> I have a question :
>>>>>>> on my laptop (debian sid), I have a second monitor on the VGA output.
>>>>>>>
>>>>>>> I don't have any problem on the VGA output when the monitor has the same
>>>>>>> display resolution (1400x1050) as the LVDS monitor.
>>>>>>> But when my second monitor has a lower resolution (1024x768), I can have
>>>>>>> a correct "clone" mode : on the second monitor I have a part of the
>>>>>>> "big" one (a rectangle 1024x768).
>>>>>>>
>>>>>>> Is there something to do ?
>>>>>> What exactly are you trying to do?  With clone mode you can have
>>>>>> either dis-similar modes on each head (1400x1050 on one, 1024x768 on
>>>>>> the other) or a common mode on both heads (e.g., 1024x768 on both).
>>>>>>
>>>>>> Alex
>>>>> Hi,
>>>>>
>>>>> I'm trying to have dis-similar modes on each head (1400x1050 on one,
>>>>> 1024x768 on the other) in clone mode...but it doesn't work.
>>>>>
>>>>> I have my main screen (LVDS) in 1400x1050 and my second (VGA) in
>>>>> 1024x768. But on the VGA one, I don't have my complete desktop, just a
>>>>> part of it (a rectangle, which its size is 1024x768 of the complete
>>>>> image (1400x1050)).
>>>> It does work.  1024x768 is smaller than 1400x1050 so you won't be able
>>>> to see all of the larger screen on the smaller one.  As Rafal
>>>> suggested you could down-scale the image on avivo class hw (r5xx and
>>>> newer), but the ati driver doesn't currently support downscaling.
>>>> Pre-avivo chips (r1xx-r4xx) only support upscaling.
>>>>
>>>> Alex
>>> Ah ok.
>>>
>>> Thx for the explanation. And Can I use radeonhd driver for my radeon
>>> 9600 mobility ?
>>
>> No, it's only supported by xf86-video-ati.  Plus since it's an r3xx
>> card, it only supports upscaling.
>>
>> Alex
>
> Ok thx again!
>

If your monitor supports it, you can switch the VGA port to 1400x1050
using xrandr or switch the LVDS port to 1024x768, then both heads will
be the same size.

Alex