laptop/graphics card to HP DreamColor LP2480ZX

Luc Verhaegen libv at
Mon Sep 7 13:53:49 PDT 2009

On Mon, Sep 07, 2009 at 09:46:32PM +0200, Kai-Uwe Behrmann wrote:
> Hello,
> has anyone sucessfully connected the DreamColor device with 10-bit/channel 
> to a laptop? I would like to work and demo the HP on its full 
> capabilities.
> What I have read on HP's monitor page is that simply HDMI 1.3 or 
> preferedly a DisplayPort 1.1 connector is needed to drive the device at 
> 10-bit. There is no compatibility hardware list to tell more if something 
> is against a recent AMD or Nvidia. So I simply assume the HP will work 
> flawlessly at 10-bits with any new hardware at least in OpenGL views.
> kind regards
> Kai-Uwe Behrmann
> -- 
> developing for colour management 
> +

About a year ago, over a weekly beer, I heard viavia that some
developer, when confronted with dream colour, had said something along
the lines of: "10 bits per channel? I can do all of that inside
$MyLittleWM!" :)

There is no point in a dreamcolour monitor unless you are actually 
feeding this monitor 30bit colour. This has nothing to do with what the 
layout in the framebuffer or drawables is like. If you have a 30bit 
framebuffer, but still feed your monitor a 24bit digital signal, then 
you're really mostly fooling yourself :)

ATI R5xx and up hardware does 10bits internally throughout the 
modesetting chain, but unless the digital outputs are adjusted 
correctly, your monitor will not get this. Of course, it could be that 
for many generations, this was not tested properly and that therefor 
older hw might not work properly or might need special workarounds or 
that atombios does not help you to set this up.

I believe that nvidia did the legwork at the dix side as iirc they made 
it work with their binary-only driver.

Luc Verhaegen.

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