6 Replies Latest reply on Oct 13, 2015 12:36 PM by jeff_fire

    Triple Monitor Setup

    classical_muse

      I have 2 Asus VS239 IPS monitors, and an AOC monitor (not sure which, lost the box). I'm having trouble setting up a third monitor on my pc using 2 7870's in crossfire. I have the 2 Asus' hooked up already, both using DVI cables. I tried switching one with an HDMI and giving the DVI to my AOC, but the Asus stopped getting a signla with the HDMI. Windows still detects it, but not as a working monitor and CCC doesn't see it at all. I had a DisplayPort to DVI adapter, so I plugged my AOC into that, but the HDMI Asus still won't recieve a signal. What combination do I need to get this to work? 

        • Re: Triple Monitor Setup
          Thanny

          You need an active DisplayPort adapter for one of the monitors.

            • Re: Triple Monitor Setup
              jeff_fire

              But that just isn't true - I used to run a pair of old 4850s in crossfire with three monitors, all using DVI cables (some with DVI-HDMI cables). I Now have a 270X and have been running three monitors using 1DP, 1 HDMI and one DVI-HMDI. Since upgrade to Windows10 I have the same issue but this is not a hardware limitation because it worked effortlessly out of the box pre-Win10.

               

              Can someone at least confirm this is a software issue that is being worked on rather than insisting we need an active DP because that just isn't true.

                • Re: Triple Monitor Setup
                  Thanny

                  4850's didn't support three monitors, period.  If you had three monitors connected to two of them, you weren't using CrossFire, as that requires all monitors to be connected to the primary card.

                   

                  Since you're using DisplayPort with one display, whatever issue you're having isn't the same as the original poster's.  I've seen a great many posts about multiple monitor problems in Windows 10, so I suspect there's something generally wrong there.  Whether it's the OS or AMD's driver for it, I couldn't say.  I'm not going near Windows 10 for at least a few more months.

                    • Re: Triple Monitor Setup
                      jeff_fire

                      Yes, you are of course correct - I didn't have crossfire enabled then.

                       

                      However, the original poster has also tried using a DisplayPort too. Windows 10 working a treat other than this and I suspect is is an AMD issue as all three monitors are detected but catalyst insists on disabling the second to enable the third.

                       

                      What irritates me is reading on multiple forums that we need to buy an active DP adapter when that is not necessary - can we have a confirmed issue here? Will we see a software resolution?

                        • Re: Triple Monitor Setup
                          Thanny

                          There are two cases where an active DP adapter isn't needed for three monitors on a single card.  The first is if the card is a Sapphire FleX model, which allows three connections over DVI/HDMI.  The second is if it's a 290X or higher card and all three monitors are identical, which also requires having all three monitors connected and powered on at boot time.

                           

                          For all other cases, using a third monitor on a single card requires a DisplayPort connection.  That includes the case of the original poster, who tried nothing but a passive DisplayPort adapter.

                           

                          In other words, your assertion is simply incorrect, and there's no software fix to be made - it's a hardware limitation.

                            • Re: Triple Monitor Setup
                              jeff_fire

                              But then we are back to where we are started.

                               

                              I have a 270x and three identical monitors: one connected by HDMI-HDMI, one by DP-HDMI and one by DVI-HDMI. This set up worked under Win8 with no fiddling, it just worked right out of the box. The only limitation I found was that I could not use both of the DVI ports at the same time as another port but using the DP, the HDMI and one of the DVI outputs worked effortlessly.

                               

                              This can not be a hardware limitation hence my frustration at being repeatedly told as much