12 Replies Latest reply on Jun 10, 2009 4:45 AM by irdinc

    AMD stream doesn't detect 2 x 4870

    Michal.Kierzynka

      Hi to all,

      I have two radeon 4870. I have CrossfireX turned off. Driver version: 9.4, OS: Windows XP 32bit. When I run "FindNumDevises" program delivered with CAL the output is:

      Supported CAL Runtime Version: 1.3.185
      Found CAL Runtime Version: 1.4.255
      Use -? for help
      CAL initialized.
      Finding out number of devices :-
      Device Count = 1
      CAL shutdown successful.

       

      Why does this program detect only one device? Any advices?

       

        • AMD stream doesn't detect 2 x 4870
          ryta1203

          Read the FAQ.

          EDIT: I thought I saw in a FAQ (that I can't find now of course ) that you have to turn Crossfire ON, which I oddly thought contradicted AMDs early statements that Crossfire needed to be off, but hey, what do I know.

            • AMD stream doesn't detect 2 x 4870
              Michal.Kierzynka

              You're absolutely right. Thanks. The CrossFireX must be enabled. But to be honest, I found it a bit confusing, because in NV CUDA the SLI must be actually disabled.

                • AMD stream doesn't detect 2 x 4870
                  emuller

                  In Linux, crossfire should not be enabled, and I imagine this is true for Windows as well.

                  There are clear instructions for both Windows and Linux in <atical>/CAL_Documentation/CAL_FAQ.pdf at least since the 1.4beta release.

                   

                   

                   

                   

                    • AMD stream doesn't detect 2 x 4870
                      Michal.Kierzynka

                      I read the /CAL_Release_Notes.pdf and /CAL_Documentation/CAL_FAQ.pdf.

                      Then I just wanted to edit my previous post (to correct it), but emuller was faster

                       

                      To sum up:

                      1) To have both card recognized by Stream, CrossFire doesn't have to be enabled, if you tell your OS to enable display on the second GPU (Windows -> "Extend my Windows desktop onto this monitor").

                      2) If CrossFire is enabled in WindowsXP, the amount of local memory is reduced by half.

                      3) Under Linux and Vista Stream uses only one GPU if CrossFire is enabled -> one should disable CrossFire.

                       

                        • AMD stream doesn't detect 2 x 4870
                          wgbljl

                           



                          1) To have both card recognized by Stream, CrossFire doesn't have to be enabled, if you tell your OS to enable display on the second GPU (Windows -> "Extend my Windows desktop onto this monitor").

                          How to make both cards recongnized by Stream in Linux?

                          Thanks for any help

                            • AMD stream doesn't detect 2 x 4870
                              Michal.Kierzynka

                               

                              Originally posted by: wgbljl


                               

                              1) To have both card recognized by Stream, CrossFire doesn't have to be enabled, if you tell your OS to enable display on the second GPU (Windows -> "Extend my Windows desktop onto this monitor").

                               

                               

                              How to make both cards recongnized by Stream in Linux?

                               

                              Thanks for any help

                               

                               

                              The answer is in "/atical/CAL_Documentation/CAL_FAQ.pdf" file.

                               

                            • AMD stream doesn't detect 2 x 4870
                              riza.guntur

                               

                              Originally posted by: Michal.Kierzynka I read the /CAL_Release_Notes.pdf and /CAL_Documentation/CAL_FAQ.pdf.

                               

                              Then I just wanted to edit my previous post (to correct it), but emuller was faster

                               

                               

                               

                              To sum up:

                               

                              1) To have both card recognized by Stream, CrossFire doesn't have to be enabled, if you tell your OS to enable display on the second GPU (Windows -> "Extend my Windows desktop onto this monitor").

                               

                              2) If CrossFire is enabled in WindowsXP, the amount of local memory is reduced by half.

                               

                              3) Under Linux and Vista Stream uses only one GPU if CrossFire is enabled -> one should disable CrossFire.

                               

                               

                               

                              How do I extend windows desktop if I currently only have one monitor attached? I have deactivated crossfirex. The extend checkbox haven't checked after the confirmation.

                              So far I found the gpu memory is really small, thus by consider I have 2 4850 512MB I would like to sum up the memory of both cards in XP 32.

                              In samples with crossfirex on, I try to use the second gpu to calculate matrix multiplication and the result seems better by tens GFLOPS. When the dimension of matrix goes beyond 5000, the program crashed. I think it because the memory is not enough.

                              Does anyone have a clue?

                                • AMD stream doesn't detect 2 x 4870
                                  Michal.Kierzynka

                                   

                                  How do I extend windows desktop if I currently only have one monitor attached? I have deactivated crossfirex. The extend checkbox haven't checked after the confirmation.

                                  I have the same problem. Maybe some KVM switch would help. I'll have to give it a try.

                                   

                                  So far I found the gpu memory is really small, thus by consider I have 2 4850 512MB I would like to sum up the memory of both cards in XP 32.

                                   

                                  In samples with crossfirex on, I try to use the second gpu to calculate matrix multiplication and the result seems better by tens GFLOPS. When the dimension of matrix goes beyond 5000, the program crashed. I think it because the memory is not enough.

                                   

                                  Does anyone have a clue?

                                   

                                  I don't understand your problem exactly. If you want to have 2x 512MB (1GB), crossfire have to be disabled.

                                   

                                    • AMD stream doesn't detect 2 x 4870
                                      riza.guntur

                                       

                                      Originally posted by: Michal.Kierzynka


                                       

                                       

                                       

                                      How do I extend windows desktop if I currently only have one monitor attached? I have deactivated crossfirex. The extend checkbox haven't checked after the confirmation.

                                       

                                       

                                      I have the same problem. Maybe some KVM switch would help. I'll have to give it a try.

                                       

                                       

                                       

                                       

                                      So far I found the gpu memory is really small, thus by consider I have 2 4850 512MB I would like to sum up the memory of both cards in XP 32.

                                       

                                       

                                       

                                      In samples with crossfirex on, I try to use the second gpu to calculate matrix multiplication and the result seems better by tens GFLOPS. When the dimension of matrix goes beyond 5000, the program crashed. I think it because the memory is not enough.

                                       

                                       

                                       

                                      Does anyone have a clue?

                                       

                                       

                                       

                                       

                                      I don't understand your problem exactly. If you want to have 2x 512MB (1GB), crossfire have to be disabled.

                                       

                                       

                                       

                                      I mean: Do I still get 1GB and computing power of 2x4850 after disabling CF but the extend desktop still haven't been checked after I tried to check it?

                                      Do you get it? sorry for my bad English