Re: [Feature request] Multiple X servers on one graphics card?

["Prof. Dr. Klaus Kusche" <klaus.kusche@computerix.info>]

On 2011-08-02 14:59, Alex Deucher wrote:
> On Mon, Aug 1, 2011 at 3:41 PM, Prof. Dr. Klaus Kusche
> <klaus.kusche@computerix.info>  wrote:
>> Hmmm, what's about the opposite approach?
>> To me, it sounds simpler and more logical when the kernel always creates
>> one device node per output (or maybe dynamically per connected output),
>> without any need for configuration or device assignment.
>
> You almost always have more connectors than display controllers (e.g.,
> you might have displayport, svideo, DVI-I and VGA, but only two
> display controllers so you can only use two of the connectors at any
> time).  Also certain combinations of connectors are not possible
> depending on the hw (e.g., the svideo and the VGA port may share the
> same DAC, so you can only use one or the other at the same time).

Hmmm, for my purposes I was only thinking about new, current hardware,
not about previous-generation cards, and only about digital outputs:

* The professional, high-quality solution would be ATI's FirePro 2460:
4 mini Displayports, all active at the same time, single slot
(passive cooling, < 20 W, so that's a great energy saver, too,
competing with thin and zero clients,
and it's silent and long-lived)

* The XFX HD-677X-Z5F3 most likely offers most ports per Euro and space:
5 mini Displayports, all active at the same time, single slot,
for less than 100 Euro

(this would result in 16/20 seats with any quad-crossfire mainboard
and 28/35 seats with some server mainboards if the BIOS is able
to assign addresses to 7 graphics cards)

Even the low-cost 6450 supports 3 and the 6570 supports 4
independent simultaneous outputs, so any ATI 6xxx card can drive
all its outputs at the same time
(and I believe that was also true for ATI 5xxx)
However, cards with 3 or 4 digital outputs are hard to find
in that price range... (XFX HD6570 is one of them)

But you're correct, my suggestion above needs to be refined:
One DRI device per display controller.

Klaus.

-- 
Prof. Dr. Klaus Kusche
Private address: Rainstraße 9/1, 88316 Isny, Germany
+49 7562 6211377 Klaus.Kusche@computerix.info http://www.computerix.info
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+49 7562 9707 36 kusche@nta-isny.de http://www.nta-isny.de