Some offline testing:
device is
Intel(R) Core(TM) i5-3470 CPU @ 3.20GHz
OpenCL Platform Name: Intel(R) OpenCL
Number of devices: 1
Max compute units: 6
Max work group size: 256
Max clock frequency: 350Mhz
Max memory allocation: 425721856
Cache type: Read/Write
Cache line size: 64
Cache size: 2097152
Global memory size: 1702887424
Constant buffer size: 65536
Max number of constant args: 8
Local memory type: Scratchpad
Local memory size: 65536
Queue properties:
Out-of-Order: No
Name: Intel(R) HD Graphics 2500
Vendor: Intel(R) Corporation
Driver version: 8.15.10.2656
Version: OpenCL 1.1
Extensions: cl_khr_icd 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_gl_sharing cl_khr_d3d10_sharing cl_intel_dx9_media_sharing cl_khr_3d_image_writes cl_khr_byte_addressable_store
CPU is idle:
WU : Clean_01LC.wu
AP6_win_x86_SSE_CPU_r1753.exe -verbose :
Elapsed 164.250 secs
CPU 162.241 secs
AP6_win_x86_SSE_CPU_r555.exe -verbose :
Elapsed 164.593 secs
CPU 162.600 secs
AP6_win_x86_SSE2_CPU_r1753.exe -verbose :
Elapsed 164.713 secs
CPU 162.709 secs
AP6_win_x86_SSE2_OpenCL_Intel_r1758.exe -verbose :
Elapsed 198.185 secs
CPU 165.876 secs
AP6_win_x86_SSE2_OpenCL_Intel_r1761.exe -verbose :
Elapsed 198.022 secs
CPU 165.517 secs
AP6_win_x86_SSE3_CPU_r1753.exe -verbose :
Elapsed 168.799 secs
CPU 166.796 secs
AP6_win_x86_SSE3_CPU_r555.exe -verbose :
Elapsed 170.812 secs
CPU 168.715 secs
3 CPU core of 4 busy with BOINC (1 core idle):
WU : Clean_01LC.wu
AP6_win_x86_SSE_CPU_r1753.exe -verbose :
Elapsed 194.390 secs
CPU 191.398 secs
AP6_win_x86_SSE_CPU_r555.exe -verbose :
Elapsed 194.258 secs
CPU 191.881 secs
AP6_win_x86_SSE2_CPU_r1753.exe -verbose :
Elapsed 190.192 secs
CPU 188.012 secs
AP6_win_x86_SSE2_OpenCL_Intel_r1758.exe -verbose :
Elapsed 243.065 secs
CPU 206.811 secs
AP6_win_x86_SSE2_OpenCL_Intel_r1761.exe -verbose :
Elapsed 240.133 secs
CPU 203.847 secs
AP6_win_x86_SSE3_CPU_r1753.exe -verbose :
Elapsed 192.979 secs
CPU 190.961 secs
AP6_win_x86_SSE3_CPU_r555.exe -verbose :
Elapsed 200.139 secs
CPU 197.747 secs
All CPU cores busy with BOINC (AKv8 tasks) (that is, CPU overcomitted for CPU app):
WU : Clean_01LC.wu
AP6_win_x86_SSE_CPU_r1753.exe -verbose :
Elapsed 353.085 secs
CPU 197.840 secs
AP6_win_x86_SSE_CPU_r555.exe -verbose :
Elapsed 378.552 secs
CPU 188.278 secs
AP6_win_x86_SSE2_CPU_r1753.exe -verbose :
Elapsed 396.007 secs
CPU 196.686 secs
AP6_win_x86_SSE2_OpenCL_Intel_r1758.exe -verbose :
Elapsed 268.419 secs
CPU 2.465 secs
AP6_win_x86_SSE2_OpenCL_Intel_r1761.exe -verbose :
Elapsed 270.763 secs
CPU 2.886 secs
AP6_win_x86_SSE3_CPU_r1753.exe -verbose :
Elapsed 242.125 secs
CPU 197.294 secs
AP6_win_x86_SSE3_CPU_r555.exe -verbose :
Elapsed 270.572 secs
CPU 195.797 secs
As one can see, though freeing CPU core speedups GPU app whole system performance should be better if GPU app works with all cores busy.
