5 Replies Latest reply on Oct 2, 2015 1:43 PM by xudonax

    Crossfire with PCIe from chipset

    xudonax

      Hi all,

       

      I've got a motherboard which has two PCIe 2.0 x16 connections directly to the north bridge, and one PCIe 2.0 x4 connection to the south bridge as shown in the block diagram below. I'm wondering, would it be possible to run two or three R9 Fury X cards in CrossFire across those connectors? I'm guessing the two PCIe x16 connectors are no issue as these are connected to the same north bridge, but could I also use the single x4 connector?

       

      At the moment I only have one 3440x1440 display, but I'm considering adding two 2560x1440 to either side to create a (slightly) more immersive experience.

      block_diagram.png

      The motherboard is an "old" Tyan Tempest i5400PW S5397, but seeing how it's still perfect for my demands and wishes with the dual CPU's. The i5400B is an Intel 5400 chip, in the same way that the 6321ESB is an Intel 6321ESB chip.

       

      Thanks,

      Xudonax

        • Re: Crossfire with PCIe from chipset
          amdmatt

          Hi Patrick Bregman,

           

          In theory this should work, however in some instances you may be bottlenecking the X2 Fury. I would probably recommend you stick with x2 Fury X on the faster lanes.

          2 of 2 people found this helpful
            • Re: Crossfire with PCIe from chipset
              systembuilder

              I've wanted to do something SIMILAR to this with an APU, an R7, and a pair of R9's.... so you're saying Matt that such a setup is perfectly viable?

                • Re: Crossfire with PCIe from chipset
                  amdmatt

                  Hi Jason Seiler,

                   

                  If i understand it correctly, you're wishing to use a Dual Graphics set up (APU+R7 Discrete Graphics Card) with a regular R9 CrossFire setup. If this is incorrect please let me know as my response will change.

                   

                  This kind of configuration is not possible. Dual Graphics cannot work in combination with a pair of regular discrete Graphics Cards in CrossFire.

                   

                  Please refer to our CrossFire and Dual Graphics FAQ for more information.

                   

                   

                  I will be able to make some product recommendations to you if you can provide the following information.


                  What you are trying to achieve?

                  What games you play?

                  What resolution you will be running?

                    • Re: Crossfire with PCIe from chipset
                      systembuilder

                      Gigabyte GA-F2A88X-UP4

                      AMD A10 Godavari 3.9Ghz

                      16GB PC 1600 Corsair

                       

                      Radeon R9 280X 3GB (Dual)

                      Radeon R7 250 2GB (in PCIE 2.0 4x slot)

                       

                       

                      1) Disable Onboard Audio in order to free up extra PCIE lanes in chipset which will speed up the PCIE slots (including the R7).  Use AMD TrueAudio output.

                      2) Crossfire the APU R7 to the R7 250X in PCIE slot #3 into Hybrid Crossfire.

                      3) Crossfire the R9 280X's in PCIE #1 and #2 into Dual Crossfire.

                      4) Windows 10 SHOULD combine the Hybrid Crossfire R7's to the Dual Crossfire R9's.

                       

                      While under Windows 8 this would have been impossible, a recent experement I tried with my Phenom II computer suggests that this could be a workable option.  With Windows 10, I tried ENABLING the Radeon 3200 IGP which has been laying dorment since DirectX 11.  Not only did it enable without crashing, it DID Hybrid Crossfire in with my Radeon R9 and I did get a 3% performance increase as the 512MB of RAM assigned to the Radeon 3200 was made available to the R9.  I'm debating taking the concept to the next step by seeing just how much GPU Windows 10 and AMD will let you throw together... and if the R7 does not work in an Crossfire configuration as I imagine, would adding an R7 to the APU setup offer extra support for HSA?

                      It seems possible. A10, R7 250 and R9 280X are the same generation of DirectX.  Crossfire does allow up to 4 GPU's... and each card mentioned is a single GPU.  Windows 10 adjusts performance based on total number of GPU's and performance of each.  A10 and R7 250 is correct identical match.  Identical 280X cards are identical match.  What I'm counting on is Windows 10 combining the GPU's as advertised.  Only question is:  Will the A88X be up to it?

                       

                      Already own a pair of 280X cards... and I am going to be doing Star Citizen 1080p...

                  • Re: Crossfire with PCIe from chipset
                    xudonax

                    Alright, thanks! Then I'll just stick with the plan to get two Fury X cards for this setup, should be plenty for 8560x1440 I guess