Announcement

Collapse
No announcement yet.

Mesa 20.1 Sees Big Optimizations To Its Soft FP64 Implementation

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Mesa 20.1 Sees Big Optimizations To Its Soft FP64 Implementation

    Phoronix: Mesa 20.1 Sees Big Optimizations To Its Soft FP64 Implementation

    For the past year Mesa has offered a "soft" implementation of FP64 capabilities for GPUs lacking FP64 hardware capabilities in order to support ARB_gpu_shader_fp64 as required by OpenGL 4.0. Optimizations were merged today to significantly enhance the "soft FP64" capabilities of Mesa...

    http://www.phoronix.com/scan.php?pag...ized-Soft-FP64

  • #2
    Will there be benchmark of this?
    ## VGA ##
    AMD: X1950XTX, HD3870, HD5870
    Intel: GMA45, HD3000 (Core i5 2500K)

    Comment


    • #3
      Originally posted by darkbasic View Post
      Will there be benchmark of this?
      Is there any real application that use it to benchmark?

      Comment


      • #4
        Originally posted by Nille_kungen View Post
        Is there any real application that use it to benchmark?
        As well as any practical hardware in 2020 relying on it.
        Michael Larabel
        http://www.michaellarabel.com/

        Comment


        • #5
          Loosely connecting to the topic, but I have a TeraScale3 (r600g) card which has FP64 hardware support (so don't need this software emulation) and thus practically supports OpenGL up to 4.5. With Mesa 20.0.1 the glxinfo only shows 4.3 (core) support in the case of this card and I also have GCN1 and GCN5 cards with OpenGL 4.6 capability and they only expose 4.5 support. Which is interesting, because the MesaMatrix is clearly showing OGL 4.5 and 4.6 support in the two cases. Do you have any idea what can be the problem? The distro is Arch Linux.

          To the topic: I think when this software FP64 support implemented the older TeraScale1/2 GPUs also could in theory support OGL 4.5. For older games running under Wine this can be useful.

          Comment


          • #6
            Originally posted by G-P-L View Post
            Loosely connecting to the topic, but I have a TeraScale3 (r600g) card which has FP64 hardware support (so don't need this software emulation) and thus practically supports OpenGL up to 4.5. With Mesa 20.0.1 the glxinfo only shows 4.3 (core) support in the case of this card and I also have GCN1 and GCN5 cards with OpenGL 4.6 capability and they only expose 4.5 support. Which is interesting, because the MesaMatrix is clearly showing OGL 4.5 and 4.6 support in the two cases. Do you have any idea what can be the problem? The distro is Arch Linux.

            To the topic: I think when this software FP64 support implemented the older TeraScale1/2 GPUs also could in theory support OGL 4.5. For older games running under Wine this can be useful.
            For the r600 card, I believe the driver is artificially limited to 4.3 because Khronos added validation/testing requirements for being able to support GL 4.4 and above.

            By the time such support was added to the driver, AMD wasn't interested in getting it officially validated, and seemed to want to avoid claiming it was compatible without the tests.

            However, the driver does support all the necessary functionality, so all you have to do is force the correct GL version via an environment variable and it should work.


            For the GCN cards, is Mesa built with the NIR backend enabled by default? If it's using TGSI, that will limit it to 4.5. There should be another environment variable to force that, so you could see if that enables 4.6 for you.

            Comment


            • #7
              Originally posted by Michael View Post

              As well as any practical hardware in 2020 relying on it.
              Well I still have this old tablet PC with an AMD C-60 APU. Soft64FP implementation is relevant for that GPU. So yeah, I'm interested

              Comment


              • #8
                Originally posted by smitty3268 View Post

                For the r600 card, I believe the driver is artificially limited to 4.3 because Khronos added validation/testing requirements for being able to support GL 4.4 and above.

                By the time such support was added to the driver, AMD wasn't interested in getting it officially validated, and seemed to want to avoid claiming it was compatible without the tests.

                However, the driver does support all the necessary functionality, so all you have to do is force the correct GL version via an environment variable and it should work.


                For the GCN cards, is Mesa built with the NIR backend enabled by default? If it's using TGSI, that will limit it to 4.5. There should be another environment variable to force that, so you could see if that enables 4.6 for you.
                Thanks for your answer! You are right, I checked the supported OGL extensions which are needed to support a given OGL level and in both case (r600 and radeonsi) the extensions are there for 4.5/4.6, only the driver is not reporting the maximum supported level.

                Comment


                • #9
                  Originally posted by G-P-L View Post
                  Loosely connecting to the topic, but I have a TeraScale3 (r600g) card which has FP64 hardware support (so don't need this software emulation) and thus practically supports OpenGL up to 4.5. With Mesa 20.0.1 the glxinfo only shows 4.3 (core) support in the case of this card and I also have GCN1 and GCN5 cards with OpenGL 4.6 capability and they only expose 4.5 support. Which is interesting, because the MesaMatrix is clearly showing OGL 4.5 and 4.6 support in the two cases. Do you have any idea what can be the problem? The distro is Arch Linux.

                  To the topic: I think when this software FP64 support implemented the older TeraScale1/2 GPUs also could in theory support OGL 4.5. For older games running under Wine this can be useful.
                  I don't have my NI hardware (hardware FP64) any more but as i can remember it Supported OpenGL4.5 when i checked glxinfo.
                  I now use RavenRidge and it shows as OpenGL 4.6
                  The softFP64 is already included as far as i understand so i don't think it will change anything like that.
                  Originally posted by sandy8925 View Post

                  Well I still have this old tablet PC with an AMD C-60 APU. Soft64FP implementation is relevant for that GPU. So yeah, I'm interested
                  You might need it for OpenGL 4.5 support but i don't think you will ever use it.
                  What application use FP64?

                  Comment

                  Working...
                  X