[CentOS] Video projector vs. onboard video card

Mon Sep 23 12:21:23 UTC 2019
Giles Coochey <giles at coochey.net>

On 23/09/2019 13:10, Nicolas Kovacs wrote:
> Hi,
> I have a CentOS 7 desktop client installed on an old Dell Optiplex
> computer with an Intel video card integrated into the motherboard. The
> card has a single VGA connector, and the 19" monitor is connected to it.
> I wonder how I could connect a video projector to this computer while
> keeping the monitor, in a mirroring configuration, e. g. output is the
> same on the video projector and the monitor.
> Do I have to replace my onboard video card by something like an NVidia
> GT710 graphic card with two video connectors ? Or is there a different
> solution for this?
If you are not concerned about not being able to dual-screen (i.e. have 
different things displaying on the monitor to what is on the projector, 
then the easiest way is to just get a VGA splitter.


If you do want to dual-screen, you should replace the embedded intel 
with a dual-screen compatible card with the appropriate output 
connectors. This is sometimes useful for presentations, as you can put 
the presentation on the projector and keep presentation notes on the screen.

I think most Optiplex systems support this, things to check:

* Look in the BIOS for the system, there should be a setting about which 
GPU to use, without an additional card inserted in the system the only 
working option here would be something like "Integrated Graphics", but 
when you fit a new GPU to a slot the new GPU will become an option or it 
may allow you to choose a PCIe (or AGP on older systems) - this could 
give you a clue about what type of GPU you need to get.

* Check the form factor (i.e. size of slot & space available) - some 
Optiplexes are small, so you might need a low form-factor card.

* Check slot type, most cards today are PCIe, older models might only 
have a AGP card - which will be harder to find new.

* Check bandwidth of PCIe slot - most whizzy cards need a x16, Optiplex 
might only have a x8 or x4.

Giles Coochey