[SFS] Trouble with CentOS7 box with 3 monitors ...

[Matt James]

I'll echo some of Davide's comments with my suggestions:

1) Try a different distro - I've hit many hardware issues that were
easily identified as software / driver limitations by using this
troubleshooting option.  That is to say if it works on one distro and
not another, you know you're battling a kernel / driver issue - not an
issue with the hardware itself.  You could even try (I'm ashamed that
I'm suggesting this on a Linux list..) loading up Winblows to see if
everything "just works."

2) I've also had issues with multiples of identical graphics cards.
You might start by checking to see if they play nice running ONE
display off of each card.  If you can't make the two play nice
together, first try putting them in different slots (could be an IRQ
sharing type of issue). From there, I would try swapping one of the
cards for a different brand and / or try the on-board video card if it
has one.  This will tell you if you're fighting hardware limitations.

HTH

Matt James
303-949-7659

On Wed, Aug 31, 2016 at 9:20 AM, Davide Del Vento
<davide.del.vento@gmail.com> wrote:
> Not sure with NVIDIA, however I always struggled with having more than
> 2 monitors on my laptops. Until I realized that my graphic card on the
> laptop (intel chip) did not support more than 2 screens being "on" at
> the same time (I could hook 3 monitors just fine and use the GUI to
> select which ones to use, but if I switched "on" more than two, it did
> not work -- any other combination worked). Then, with latest laptop my
> employer gave me (still with intel graphic card), everything worked
> out of the box on first attempt MATE install. Upon closer examination
> of some very hidden specs of the chipset, this one supports 3 monitors
> and the previous ones did not.
>
> So I suggest you FIRST google the EXACT chipset of your cards and make sure that
> a) it supports 3 monitors at the resolution you want (both individual
> screen resolutions and total number of horizontal and vertical pixels)
> b) anyone has been able to hook them up with 3 monitors with hw
> configuration as close to yours as possible (maybe even on MS
> windows).
>
> After that, I suggest that you try some more-hw-friendly distro (e.g.
> ubuntu), maybe off a live DVD, to see if it works. Often, if it
> doesn't work out of the box with the latest Ubuntu, 95% you can't make
> it work in any other way, so give up and stop struggling.
>
> After that's done, you can start investigating how to make it work in
> your favorite distro. Often, you need a newer kernel and the
> corresponding newer drivers.
>
> Good luck.
> Davide
>
> On Tue, Aug 30, 2016 at 9:09 PM, marcoz <marcoz@osource.org> wrote:
>> Hi all,
>>
>>  I'm usually just a lurker on this list but I've got a problem. One of my
>> coworkers has spent 2 days trying to get a new HP machine up and running
>> with his 3 monitor setup, with no luck. Google has been no help. He's about
>> to lose his mind.
>>
>> Has anyone worked with a 3-monitor setup? If so, might you be able to help?
>>
>> It's 2 identical Nvidia GeFoce 7xxx PCIe cards, if that matters/helps.
>>
>> thanks for any help or suggestions,
>> Matt
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