18 Replies Latest reply on Jan 4, 2017 6:37 AM by dipak

    Blender Cycles and Crimson 16.11.5

    cyseal

      Testing with Crimson 16.11.5

       

      I used this test file ps test.blend from ⚓ T50082 OpenCL issue and motion blur (AMD 7870 Pitcairn)

      Render time with 16.11.3 is 15.28 seconds

       

       

      Render time with 16.11.5 is 53.78 seconds.

      ps test161005.png

       

      Difference is 40 seconds ! That is very noticable performance drop.

      Memory usage and memory peak are the same.

        • Re: Blender Cycles and Crimson 16.10.4
          dipak

          H Sam,

          Thanks for reporting. Actually a newer version (Crimson 16.11.5) is available now. Could you please check with that driver and share your observations?

           

           

          Regards,

            • Re: Blender Cycles and Crimson 16.10.5
              cyseal

              Additional testing with 16.11.5: in rendering process Blender stops and Windows is giving me the message something like

              Driver stopped responding and has been recovered.

              I haven't seen it clearly.

                • Re: Blender Cycles and Crimson 16.11.5
                  dipak

                  Hi Sam,

                  Here is my finding (please check the timing) after running the attached blender file with Crimson 16.11.5 using the latest blender build (blender-2.78-05b181f-win64).

                   

                  ps test.jpg

                   

                  I ran it for multiple times with the "Motion Blur" option and observed more or less similar timing (i.e. within 15-17 seconds). Only for the first run, the timing was higher (close to 60 seconds) because of the kernel loading and building.

                  Did you refer the first run timing? Or Did I miss something during the testing? Just want to make sure that we are on same page.

                   

                  P.S. Rendering without the motion blur option, I got the same observation as you mentioned here ⚓ T50082 OpenCL issue and motion blur (AMD 7870 Pitcairn)

                   

                  Regards,

                    • Re: Blender Cycles and Crimson 16.11.5
                      cyseal

                      Ah yes, when installing new version, kernel resets itself and takes more time to render in the first run. I forgot about that.

                      If you render without motion blur checked I got only 3.07 seconds to render but with almost black screen. User from the https://developer.blender.org/T50082

                      got 2.96 seconds without motion blur.

                       

                      When I render more complex scene with sampling about 2000, Blender sometimes freezes and I got message about driver stoppped responding and had reset.

                      I used latest Blender version and 16.11.5.

                       

                      ps test3.png

                       

                      Is it possible to improve driver and OpenCl so that it loads the kernel faster and renders within 3 seconds particular scene?

                        • Re: Blender Cycles and Crimson 16.11.5
                          dipak

                          So, long kernel loading time is the issue here. I'll check with some other drivers and get back to you.

                          Btw, do you know how to force the blender to load the render kernels each time so that we could get the same effect as first run?

                           

                           

                          Regards,

                            • Re: Blender Cycles and Crimson 16.11.5
                              cyseal

                              Yes, kernel loading and the black screen.

                              For example Fiji and Polaris (3xx and 4xx) cards do not have black screen issue. This was reported before.

                              Btw, do you know how to force the blender to load the render kernels each time so that we could get the same effect as first run?

                              Sorry, I don't know that.

                                • Re: Blender Cycles and Crimson 16.11.5
                                  dipak

                                  Hi Sam,

                                  Here are observations regarding the two issues.

                                   

                                  Issue 1: Long time difference

                                  Actually the time difference is not there if you consider the kernel loading time for both the cases. Normally kernel loading (hence compiling) happens for first run and it saves those compiled kernels (CLBIN files in <user>\AppData\Roaming\Blender Foundation\Blender\<version>\cache\kernels). Next onward, it loads the compiled kernels if they exist (even though driver is different). So, the total render time is much less. I guess, your observed time difference is for that reason only. Please remove those CLBIN files before each run and check.

                                  [As I checked for both the drivers with and without motion blur options, I didn't observe much difference. Please find the attached files for details.]

                                   

                                  Issue 2: Not rendering properly without the motion blur option

                                  My observation was same as yours. It's also working fine on Hawaii. So, as reported you earlier, the problem seems with SI cards only. I'll report this to concerned team.

                                   

                                  Regards,

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