Bug#529178: video-radeon: Probably hardware limitation

[Michal Suchanek]

2009/7/22 Alex Deucher <alexdeucher at gmail.com>:
> On Wed, Jul 22, 2009 at 3:47 PM, Michal Suchanek<hramrach at centrum.cz> wrote:
>> Package: xserver-xorg-video-radeon
>> Followup-For: Bug #529178
>>
>> This is probably a hardware limitation of the card.
>>
>> AFAIK dual-link dvi is needed for modes above 1280x1024 to work reliably
>> over DVI. Some card - monitor combinations might work but others would
>> not.
>>
>> Better cards have higher-rate transmitters that can do modes slightly
>> larger than 1280x1024 but a 22" screen is likely over-spec for any
>> single link card so there is no guarantee it will work.
>
> 165 Mhz is the single link limit.  With reduced blanking you can run
> 1920x1200 at 60Hz.  Most dual link monitors start out around 2560x1600.
>

Well, reduced blanking is like overclocking. It might work but it might not.

Either way my experience with Radeon 9250 is that it cannot drive a
22" screen over DVI reliably, and I read in a bug report somewhere
somebody testing about a dozen cards with similar results.

It might be that these older cards actually cannot do full 165 MHz.

Radeon 9600 is a higher model than 9250 but it is about as old as the
9250s, perhaps even older. While it may offer better 3D performance it
might not offer better DVI transmitter than the lower models.

Thanks

Michal