[ltp] Re: X60 produces fuzzy VGA output in high resolutions - will Ultrabase help?

[Richard Neill]

Henrique de Moraes Holschuh wrote:
> On Wed, 08 Apr 2009, Marius Gedminas wrote:
>> On Tue, Apr 07, 2009 at 10:31:13AM -0400, Stefan Monnier wrote:
>>>> rate the quality is quite good, but if I go all the way to 1680×1050 px
>>>> the refresh rate drops to 60 Hz (or maybe 50 Hz, I can?t check at the
>>>> moment) and my external screen looks a bit fuzzy, much worse than the
>>> Do you know why the refresh rate drops?  I was running a 1800x1400
>>> screen at 70Hz with a measly Matrox Millenium ten years ago, so I'm
>>> pretty sure the X60 is able to provide higher refresh rates.
>> I expect LCD monitors do not advertise modes with higher refresh rates
>> in their EDID info.
> 
> The bandwidth is limited, as you increase resolution, you have to drop the
> refresh rate to keep within the limited bandwidth.
> 
> This is far worse on DVI than VGA as far as the connection goes, but the
> monitor and GPU themselves have output bandwidth limitations (maximum pixel
> clock, etc).

There are some xorg tricks, including overriding the EDID frequency, and 
  setting reduced-blanking that may help.

Richard