6 Replies Latest reply on Oct 26, 2011 5:58 AM by Atmapuri

    HD6950 and double precision!

    Atmapuri

      Hi!

      I have a Cayman HD6950 and it reports that fp64 extension is not supported. How can that be? Is that disabled in the drivers?

      Thanks!
      Atmapuri

       

        • HD6950 and double precision!
          Meteorhead

          That depends on what OS-driver-SDK you are using.

          Although reading the release notes of SDK 2.5 it says:

          The Khronos FP64 extension is supported for the ATI Radeon™ HD 5900 and 5800 series, as well as the AMD FirePro™ V8800 and V8700 series.

          6xxx cards are not mentioned for fp64 support. You might have to use cl_amd_fp64 extension for similar functionality.

            • HD6950 and double precision!
              Atmapuri

              Hi!

              Check for cl_amd_64f returns true, but check for cl_khr_fp64 returns false. Why? Double precision does not function right?

              Thanks!
              Atmapuri

               

                • HD6950 and double precision!
                  genaganna

                   

                  Originally posted by: Atmapuri Hi!

                   

                  Check for cl_amd_64f returns true, but check for cl_khr_fp64 returns false. Why? Double precision does not function right? Thanks! Atmapuri

                   

                  Atmapuri,

                  As per SDK2.5, both cl_amd_fp64 and cl_khr_fp64 are supported on this device.  

                  Are you using SDK2.5 or old?  

                    • HD6950 and double precision!
                      Atmapuri

                      Hi!

                      I am using SDK 2.5. I can only double confirm that:

                      clGetDeviceInfoStr(FDeviceID, CL_DEVICE_EXTENSIONS, Length(aStr), aStr, ParamSize));

                      Returns without cl_khr_fp64 listed. On the other hand, all double precision functions seem to work fine on CPU and GPU. (including sinh, cosh, tanh, which are listed as absent for cl_amd_64fp)

                      Is there a better way to check for support for double precision?

                      Thanks!
                      Atmapuri

                       

                       

                        • HD6950 and double precision!
                          genaganna

                           

                          Originally posted by: Atmapuri Hi!

                           

                          I am using SDK 2.5. I can only double confirm that:

                           

                          clGetDeviceInfoStr(FDeviceID, CL_DEVICE_EXTENSIONS, Length(aStr), aStr, ParamSize));

                           

                          Returns without cl_khr_fp64 listed. On the other hand, all double precision functions seem to work fine on CPU and GPU. (including sinh, cosh, tanh, which are listed as absent for cl_amd_64fp)

                           

                          Is there a better way to check for support for double precision?

                           

                          Could you please tell us your OS and Driver version?

                          Could you please run clinfo and paste output log here?

                          you can find clinfo at installerpath/bin/x86_64 or installerpath/bin/x86

                            • HD6950 and double precision!
                              Atmapuri

                              Below is clInfo. Note that cl_khr_fp64 is present for the CPU device but absent for both Caymans.

                               

                              Number of platforms:                 1
                                Platform Profile:                 FULL_PROFILE
                                Platform Version:                 OpenCL 1.1 AMD-APP-SDK-v2.5 (732.1)
                                Platform Name:                 AMD Accelerated Parallel Processing
                                Platform Vendor:                 Advanced Micro Devices, Inc.
                                Platform Extensions:                 cl_khr_icd cl_amd_event_callback cl_amd_offline_devices cl_khr_d3d10_sharing


                                Platform Name:                 AMD Accelerated Parallel Processing
                              Number of devices:                 3
                                Device Type:                     CL_DEVICE_TYPE_GPU
                                Device ID:                     4098
                                Board name:                     AMD Radeon HD 6900 Series
                                Max compute units:                 22
                                Max work items dimensions:             3
                                  Max work items[0]:                 256
                                  Max work items[1]:                 256
                                  Max work items[2]:                 256
                                Max work group size:                 256
                                Preferred vector width char:             16
                                Preferred vector width short:             8
                                Preferred vector width int:             4
                                Preferred vector width long:             2
                                Preferred vector width float:             4
                                Preferred vector width double:         0
                                Native vector width char:             16
                                Native vector width short:             8
                                Native vector width int:             4
                                Native vector width long:             2
                                Native vector width float:             4
                                Native vector width double:             0
                                Max clock frequency:                 800Mhz
                                Address bits:                     32
                                Max memory allocation:             536870912
                                Image support:                 Yes
                                Max number of images read arguments:         128
                                Max number of images write arguments:         8
                                Max image 2D width:                 8192
                                Max image 2D height:                 8192
                                Max image 3D width:                 2048
                                Max image 3D height:                 2048
                                Max image 3D depth:                 2048
                                Max samplers within kernel:             16
                                Max size of kernel argument:             1024
                                Alignment (bits) of base address:         32768
                                Minimum alignment (bytes) for any datatype:     128
                                Single precision floating point capability
                                  Denorms:                     No
                                  Quiet NaNs:                     Yes
                                  Round to nearest even:             Yes
                                  Round to zero:                 Yes
                                  Round to +ve and infinity:             Yes
                                  IEEE754-2008 fused multiply-add:         Yes
                                Cache type:                     None
                                Cache line size:                 0
                                Cache size:                     0
                                Global memory size:                 1073741824
                                Constant buffer size:                 65536
                                Max number of constant args:             8
                                Local memory type:                 Scratchpad
                                Local memory size:                 32768
                                Kernel Preferred work group size multiple:     64
                                Error correction support:             0
                                Unified memory for Host and Device:         0
                                Profiling timer resolution:             1
                                Device endianess:                 Little
                                Available:                     Yes
                                Compiler available:                 Yes
                                Execution capabilities:                 
                                  Execute OpenCL kernels:             Yes
                                  Execute native function:             No
                                Queue properties:                 
                                  Out-of-Order:                 No
                                  Profiling :                     Yes
                                Platform ID:                     000007FEF02A4348
                                Name:                         Cayman
                                Vendor:                     Advanced Micro Devices, Inc.
                                Device OpenCL C version:             OpenCL C 1.1
                                Driver version:                 CAL 1.4.1546 (VM)
                                Profile:                     FULL_PROFILE
                                Version:                     OpenCL 1.1 AMD-APP-SDK-v2.5 (732.1)
                                Extensions:                     cl_amd_fp64 cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_3d_image_writes cl_khr_byte_addressable_store cl_khr_gl_sharing cl_ext_atomic_counters_32 cl_amd_device_attribute_query cl_amd_vec3 cl_amd_printf cl_amd_media_ops cl_amd_popcnt cl_khr_d3d10_sharing


                                Device Type:                     CL_DEVICE_TYPE_GPU
                                Device ID:                     4098
                                Board name:                     AMD Radeon HD 6900 Series
                                Max compute units:                 22
                                Max work items dimensions:             3
                                  Max work items[0]:                 256
                                  Max work items[1]:                 256
                                  Max work items[2]:                 256
                                Max work group size:                 256
                                Preferred vector width char:             16
                                Preferred vector width short:             8
                                Preferred vector width int:             4
                                Preferred vector width long:             2
                                Preferred vector width float:             4
                                Preferred vector width double:         0
                                Native vector width char:             16
                                Native vector width short:             8
                                Native vector width int:             4
                                Native vector width long:             2
                                Native vector width float:             4
                                Native vector width double:             0
                                Max clock frequency:                 800Mhz
                                Address bits:                     32
                                Max memory allocation:             536870912
                                Image support:                 Yes
                                Max number of images read arguments:         128
                                Max number of images write arguments:         8
                                Max image 2D width:                 8192
                                Max image 2D height:                 8192
                                Max image 3D width:                 2048
                                Max image 3D height:                 2048
                                Max image 3D depth:                 2048
                                Max samplers within kernel:             16
                                Max size of kernel argument:             1024
                                Alignment (bits) of base address:         32768
                                Minimum alignment (bytes) for any datatype:     128
                                Single precision floating point capability
                                  Denorms:                     No
                                  Quiet NaNs:                     Yes
                                  Round to nearest even:             Yes
                                  Round to zero:                 Yes
                                  Round to +ve and infinity:             Yes
                                  IEEE754-2008 fused multiply-add:         Yes
                                Cache type:                     None
                                Cache line size:                 0
                                Cache size:                     0
                                Global memory size:                 1073741824
                                Constant buffer size:                 65536
                                Max number of constant args:             8
                                Local memory type:                 Scratchpad
                                Local memory size:                 32768
                                Kernel Preferred work group size multiple:     64
                                Error correction support:             0
                                Unified memory for Host and Device:         0
                                Profiling timer resolution:             1
                                Device endianess:                 Little
                                Available:                     Yes
                                Compiler available:                 Yes
                                Execution capabilities:                 
                                  Execute OpenCL kernels:             Yes
                                  Execute native function:             No
                                Queue properties:                 
                                  Out-of-Order:                 No
                                  Profiling :                     Yes
                                Platform ID:                     000007FEF02A4348
                                Name:                         Cayman
                                Vendor:                     Advanced Micro Devices, Inc.
                                Device OpenCL C version:             OpenCL C 1.1
                                Driver version:                 CAL 1.4.1546 (VM)
                                Profile:                     FULL_PROFILE
                                Version:                     OpenCL 1.1 AMD-APP-SDK-v2.5 (732.1)
                                Extensions:                     cl_amd_fp64 cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_3d_image_writes cl_khr_byte_addressable_store cl_khr_gl_sharing cl_ext_atomic_counters_32 cl_amd_device_attribute_query cl_amd_vec3 cl_amd_printf cl_amd_media_ops cl_amd_popcnt cl_khr_d3d10_sharing


                                Device Type:                     CL_DEVICE_TYPE_CPU
                                Device ID:                     4098
                                Board name:                     
                                Max compute units:                 4
                                Max work items dimensions:             3
                                  Max work items[0]:                 1024
                                  Max work items[1]:                 1024
                                  Max work items[2]:                 1024
                                Max work group size:                 1024
                                Preferred vector width char:             16
                                Preferred vector width short:             8
                                Preferred vector width int:             4
                                Preferred vector width long:             2
                                Preferred vector width float:             4
                                Preferred vector width double:         0
                                Native vector width char:             16
                                Native vector width short:             8
                                Native vector width int:             4
                                Native vector width long:             2
                                Native vector width float:             4
                                Native vector width double:             0
                                Max clock frequency:                 3300Mhz
                                Address bits:                     64
                                Max memory allocation:             2147483648
                                Image support:                 Yes
                                Max number of images read arguments:         128
                                Max number of images write arguments:         8
                                Max image 2D width:                 8192
                                Max image 2D height:                 8192
                                Max image 3D width:                 2048
                                Max image 3D height:                 2048
                                Max image 3D depth:                 2048
                                Max samplers within kernel:             16
                                Max size of kernel argument:             4096
                                Alignment (bits) of base address:         1024
                                Minimum alignment (bytes) for any datatype:     128
                                Single precision floating point capability
                                  Denorms:                     Yes
                                  Quiet NaNs:                     Yes
                                  Round to nearest even:             Yes
                                  Round to zero:                 Yes
                                  Round to +ve and infinity:             Yes
                                  IEEE754-2008 fused multiply-add:         No
                                Cache type:                     Read/Write
                                Cache line size:                 64
                                Cache size:                     32768
                                Global memory size:                 8493379584
                                Constant buffer size:                 65536
                                Max number of constant args:             8
                                Local memory type:                 Global
                                Local memory size:                 32768
                                Kernel Preferred work group size multiple:     1
                                Error correction support:             0
                                Unified memory for Host and Device:         1
                                Profiling timer resolution:             310
                                Device endianess:                 Little
                                Available:                     Yes
                                Compiler available:                 Yes
                                Execution capabilities:                 
                                  Execute OpenCL kernels:             Yes
                                  Execute native function:             Yes
                                Queue properties:                 
                                  Out-of-Order:                 No
                                  Profiling :                     Yes
                                Platform ID:                     000007FEF02A4348
                                Name:                                Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz
                                Vendor:                     GenuineIntel
                                Device OpenCL C version:             OpenCL C 1.1
                                Driver version:                 2.0
                                Profile:                     FULL_PROFILE
                                Version:                     OpenCL 1.1 AMD-APP-SDK-v2.5 (732.1)
                                Extensions:                     cl_khr_fp64 cl_amd_fp64 cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_byte_addressable_store cl_khr_gl_sharing cl_ext_device_fission cl_amd_device_attribute_query cl_amd_vec3 cl_amd_media_ops cl_amd_popcnt cl_amd_printf cl_khr_d3d10_sharing