According to clinfo output, my Radeon HD 6970 (lspci -nn output: 01:00.0 VGA compatible controller : Advanced Micro Devices, Inc. [AMD/ATI] Cayman XT [Radeon HD 6970] [1002:6718]) has no global cache. This is using Catalyst drivers, version 13.4. Is this an actual device limitation or a bug in the driver? The full clinfo output follows:
Device Type: CL_DEVICE_TYPE_GPU Device ID: 4098 Board name: AMD Radeon HD 6900 Series Device Topology: PCI[ B#1, D#0, F#0 ] Max compute units: 24 Max work items dimensions: 3 Max work items: 256 Max work items: 256 Max work items: 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: 2 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: 2 Max clock frequency: 880Mhz Address bits: 32 Max memory allocation: 268435456 Image support: Yes Max number of images read arguments: 128 Max number of images write arguments: 8 Max image 2D width: 16384 Max image 2D height: 16384 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: 2048 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: 0x7f5d4d6ba520 Name: Cayman Vendor: Advanced Micro Devices, Inc. Device OpenCL C version: OpenCL C 1.2 Driver version: 1124.2 Profile: FULL_PROFILE Version: OpenCL 1.2 AMD-APP (1124.2) 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_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_media_ops2 cl_amd_popcnt
well, it certainly is a bug in driver. The card certainly has caches. Can you check with 13.6 driver once.
Did you try with the latest Catalyst drivers? Does it work now?
Hello, I just tested with the latest stable (14.4) and they still report None as Global Memory cache type.