Multiple video cards

[Da Rock]

On 07/30/14 03:09, Warren Block wrote:
> On Tue, 29 Jul 2014, Zane C. B-H. wrote:
>
>> 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 Xinerama is obsolete, but don't know.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.
>
> Well, yes, except Xinerama is, I think, obsolete.  It's was what we 
> used back in the old days of single-output video boards.  There should 
> be a new xrandr way to do this.  Whether that code is part of the 
> version of xorg currently available in FreeBSD, I don't know.
I doubt xrandr will have something new specifically for this, I got a 
bit more curious about the specifics of the setup and had a look. I was 
surprised to find that xrandr can't handle 2 cards, but there you go... 
apparently the linux crew don't like xinerama taking away their eye 
candy, can't fix it with xrandr, and have just brushed past it with "why 
would you want 2 cards anyway; 1 card has the power for all" :)

This might actually prove useful to you though: 
http://nouveau.freedesktop.org/wiki/MultiMonitorDesktop/. It will be 
interesting to see what you achieve at the end of this if you get it to 
work.