Hi I'm trying to install dual monitors of different makers and sizes on my Dell workstation with Nvidia Quadro 4000 onboard, it has 2 display ports and one DVI port, the monitors does not have HDMI ports so I tried using a DVI to VGA adapter and connected it to VGA splitter, one to each monitor, they worked but they display the same thing (mirrored) I want to extend my desktop across them.

Edit : In screen resolution it doesn't show two displays only one Any ideas

  • Why do you have a VGA splitter? – D-Klotz Jan 27 '17 at 18:39
  • the card only have one DVI and two DP ports, my monitors have one DVI and one VGA – user690819 Jan 31 '17 at 14:06

The problem is that VGA cannot be "split" to two outputs, all these VGA splitters are only meant for mirroring. There is just no way that one VGA output could carry two separate signals for two monitors.

What you'd need is to buy another adapter from one of your other outputs (you write DP and HDMI as one thing, but they are two different things. Which one do you have?) to convert it as well to VGA.

This is such an adapter for Display Port: http://amzn.to/2kbCySL

And this one is for HDMI: http://amzn.to/2kbD2YQ

  • yea sorry for the mistake I meant two DP one the card but my monitors only have DVI and VGA – user690819 Jan 31 '17 at 14:03
  • If both your monitor support DVI, rather use a DP to DVI adapter than DP to VGA for the 2nd monitor. Something like this amzn.to/2kQ6dNS. Becuase VGA is an old analog technology and DVIs digital signal might be better. – Yisroel Tech Jan 31 '17 at 14:09

It sounds like it's working, you just need to change the settings. Right click on your desktop and choose "Screen Resolution". Make sure your 2nd screen is set to "Extend desktop to this display"

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Go to Control Panel > Appearance and Personalisation > Display > Adjust Resolution (on the left) and set multiple displays mode to extend.

  • I tried but it doesn't detect another display only one is shown – user690819 Jan 27 '17 at 17:02

It could be that the graphics card does not support analogue output. With DVI you can have an analog or a digital signal. With analogue a basic adaptor can convert DVI -> VGA, but if the signal is digital you need an 'active' adaptor. Active adaptors have to convert Digital to Analog so require additional power and are more expensive.

I think you may need an active DVI -> VGA adaptor.

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