Multiple video cards

[Zane C. B-H.]

On Sun, 27 Jul 2014 17:17:43 -0600 (MDT)
Warren Block <wblock at wonkity.com> wrote:

> Test system:
> 
> FreeBSD 10-STABLE amd64 r269160
> AMD A8-3850 APU (Radeon HD6550D)
> Radeon X1650 PCIe card
> 
> Under IGX Configuration, the APU motherboard BIOS has a "Surround
> View" setting.  When enabled, the onboard HD6550 GPU remains
> enabled when an additional video card is connected.
> 
> With the HD6550 disabled, the X1650 works fine.  pciconf shows only
> one video device.
> 
> With the HD6550 enabled, both video devices show in pciconf, and X
> gives the "screens not found" error unless both are defined in
> xorg.conf.  X starts, but xrandr only shows the HD6550, and only
> the monitors attached to the motherboard video connectors work.
> xrandr only shows that cards.
> 
> There may be more settings required in xorg.conf.  I think that
> Xinerama is obsolete, but don't know.
> 
> Based on some Linux stuff:
> % xrandr --listproviders
> RandR 1.4 not supported
> 
> Is there a right way to define multiple monitors on more than one
> card for the same virtual screen?

You are most likely looking at using Xinerama there, unless the
Radeon driver has something specific for it like Nvidia driver does.
The man page should give you a better idea of what exactly you need
to do.

As to configuring it, enable them both and do "X -configure" to build
it. That should autodect all cards and shove them into a config. You
will likely need to learn to do some tweaking as it rarely properly
detects the proper driver to use, meaning it will default to "vesa".
You will also need to setup all the screen you want to use in it.