Third monitor won't extend

[xanderlane]

So I've been trying to extend this old monitor to my main display, but every time I click "apply" a prompt says "Unable to save display settings."

It's an old 4:3 monitor that I am told "Is working normally". I had to plug it in with a DVI-A to VGA adapter that definitely IS working. I know this because when I unplug the main monitor it works fine.

It's detected by Windows and my 7950, but neither of them will extend it.

 

[Someone Somewhere]

What other monitors do you have connected? The 7950 can only drive two displays over non-DP links.

 

[tomate2]

for a third monitor to be used on an amd graphics card (yours is a amd graphics card)
the third monitor (or at least one of the monitors) has to be connected through a display port
three monitors connected through hdmi, dvi, or vga will not work
if you need an adapter to connect any of the monitors then it has to be an active adapter
the difference between an active adapter and a... unactive adapter? 😵 (forgot the name.. passive adapter maybe?)
active adapters have circuitry in them while passive adapters only rearrange wires so match the hdmi or dvi or vga port

 

[xanderlane]

What other monitors do you have connected? The 7950 can only drive two displays over non-DP links.

Okay, thanks. Could I use a DP to DVI? Would that count?

 

[Someone Somewhere]

Needs to be an active adapter.

Do you have two other monitors, not including the VGA one?

 

[xanderlane]

Yes, there's a 25" monitor with VGA, DVI, and HDMI and then a 21.5" with VGA and DVI

 

[Someone Somewhere]

OK, so including the VGA-only one you've got three screens.

One of these will do it: http://www.amazon.com/StarTech-com-Mini-DisplayPort-Active-Adapter/dp/B00AYAF3MQ