8 Replies Latest reply on Feb 20, 2014 6:36 AM by MikeI

    Maximum number of monitors?


      Hi all,


      I am in the process of building a new PC with an i7-4770K (HD Graphics 4600) and an Intel DH87MC motherboard.  I was hoping to attach four or five monitors to it - one via the onboard DVI connector, one via onboard HDMI, and three using a Club3D DisplayPort MST hub, connecting to the single onboard DisplayPort connector.


      However I was just reading a review of the MST hub which said that Haswell notebooks disable the built-in panel when using the hub, as these processors apparently only support a maximum of three displays.


      I can't find any other information about the maximum number of displays supported by the Haswell architecture, so I'm wondering whether anyone here knows whether this claim is true?  I hope not, because I was really hoping to be able to use more than three screens!  Adding another video card isn't really an option for me because Intel don't make discrete video cards any more, and the whole point of this upgrade was so I could use open-source Linux drivers.


      Does anyone know whether there is a limit on the number of displays supported by HD Graphics?

        • 1. Re: Maximum number of monitors?

          I've discovered in the ARK that this series of HD Graphics only supports three displays.  However I wonder whether this means number of outputs?  Since DisplayPort runs at the same rate regardless of the number of monitors connected, I was presuming the number of monitors connected via DisplayPort was entirely a software/driver issue.


          Does anyone know whether the "# of Displays Supported" option in the ARK refers to the maximum number of physical connectors, or can all these available displays be used up by a single daisy-chained DisplayPort connection, rendering the other physical connectors unusable?

          • 2. Re: Maximum number of monitors?

            The maximum support number of displays being actively used is three, no matter how many are connected.


            Currently our video controller are just designed to support triple display configurations.


            Information on how to enable this configuration is available on the following article

            Graphics | Configuration 3-Displays FAQ

            • 3. Re: Maximum number of monitors?

              Thanks for the info!  Do you know whether this is a hardware limitation?  I'm just wondering whether there is any possibility of this limit being lifted in future.

              • 4. Re: Maximum number of monitors?

                You are welcome. In fact this is a hardware limitation so this may require a future platform to work.

                1 of 1 people found this helpful
                • 5. Re: Maximum number of monitors?



                  There are two possibilities that come to mind for connecting 5 monitors. First of all, there are devices that you can connect multiple monitors to that will make these monitors appear as one big monitor to the system. For example, three 1920x1080 monitors become one virtual 5760x1080 monitor, two 1920x1080 monitors become one 1920x2060 virtual monitor, etc. Second thought is to utilize the monitor connections on an add-in graphics card. I have seen a 4x4 arrangement accomplished with two monitors connected to a graphics card and two monitors connected to the onboard graphics. In theory, five monitors should also be possible (using the third board connector) or even six monitors if the add-in graphics card supports three monitors being connected, but I myself have not seen these possibilities tried...



                  • 6. Re: Maximum number of monitors?

                    Oops, I missed an option. There are also devices that will allow you to hook up additional monitors via USB 2.0 and USB 3.0. Costs are reasonable (as low as US$$48), but you need one of these for each monitor. If you are not that concerned with having gaming-level performance, there are add-in graphics cards that will support 2 (or possibly even 3) monitors at a lower cost than multiple of these USB adapters...



                    • 7. Re: Maximum number of monitors?

                      Thanks for the suggestions, but unfortunately they aren't really an option for me.  My current PC has two nVidia cards in it running four screens, but the whole point behind me purchasing a Haswell board was that I could get away from the buggy closed source drivers provided by nVidia and AMD.  I run Linux, and on this platform Intel provide open source drivers which by many accounts are far more reliable than any other alternative, and being a programmer, it means if I encounter any problems I actually have a chance of fixing them myself without relying on the whim of some company's engineers.  (I have reported a number of bugs to nVidia which took in some cases years to get fixed.)


                      So yes, I could stick another video card in, but since Intel don't make discrete video cards it'd be from a company with sub-par drivers so I'd be back to where I am now with less than optimal reliability.


                      Your suggestion of using a device which appears as one screen but splits the image across multiple monitors would actually work quite well, but unfortunately the only device I have seen that does this only supports tiny resolutions and does not support monitor rotation.  Since I run a few screens in portrait mode at 1200x1920 and 1200x1600, I haven't found a device that can split one monitor signal into these resolutions - especially when the individual monitors differ in resolution.


                      However at least now I know there is no point in purchasing a DisplayPort MST hub, because it wouldn't allow me to connect any more monitors than the onboard connectors.

                      • 8. Re: Maximum number of monitors?

                        I know this is an old thread, but I'm in a somewhat similar situation myself. I need 5 monitors at the same time being PCI slot constrained.


                        I hope Diego could clarify a little more the hardware limitation.


                        To my understanding (and I'm no hardware expert by any means), the Ivy iGPU implemented DisplayPort 1.1. Coming from the Sandy iGPU being limited to 2 outputs, the Ivy iGPU possibly implemented some early technology of multistreaming DP, not realy the DP 1.2 MST tech. The Intel official information said that on the HD 4000 you can output to 3 monitors IF 2 of the outputs are DisplayPort. So that made me think this was some kind of a MST-like in house tech from Intel of extending the Sandy limitation of 2 outs.


                        Now, with Haswell implementing DP 1.2 my thought are:


                        1. The two DP outputs coming directly from the CPU are independent and, if they comply to the VESA standards they should, in theory, allow for 8 (eight) displays of 1920x1200 (4 on each port through independent MST).


                        2. The two DP outputs are actually multistreamed themselves, meaning you could still split or daisy chain at least 3 monitors at the mentioned resolution, or even 4 of them if only using one DP.


                        I'm using Ivy Bridge Dell systems with 2x DP 1.1 and 1x VGA and they just work for 3 monitors. Going for the 4th monitor I had to plug in an OEM graphics card providing 2 more DisplayPorts. Unfortunately, the performance significantly drops when using the OEM card and Intel's HD 4000. So my Ivy Bridge systems are DP 1.1 and my Dell monitors are also DP 1.1, no daisy chaining options.


                        I am considering getting a Haswell w/ HD 4600 or P4600 test system, either a Q87 or C226 one, also from Dell, and test the DisplayPort outputs with 9 Dell UltraSharp monitors with MST daisy chaining option built in. After seeing a block diagram for a Dell system I arrived to the conclusions above written. The DPs are controlled directly on the CPU and the VGA through the PCH with FDI.