Never checked the C1 logs...
see, for example, the file like "ImgCoreExternal.log"... there you will find info like this :
> Logging is now active.
> CPU: GenuineIntel [Intel(R) Core(TM) i7-4810MQ CPU @ 2.80GHz]
> CPU features: MMX, SSE, SSE2, SSE3, SSSE3, SSE41, SSE42, AVX, AVX2, FMA, F16C, MOVBE, CX8, RDRAND, RDTSCP
> CPU features: POPCNT, BMI1, BMI2, LZCNT
> OpenCL initialization...
> OpenCL : found platform Intel(R) OpenCL, OpenCL Version : OpenCL 1.2
> OpenCL : found platform NVIDIA CUDA, OpenCL Version : OpenCL 1.1 CUDA 6.5.35
> OpenCL Device : Intel(R) HD Graphics 4600
> OpenCL Driver Version : 10.18.14.4264
> OpenCL Compute Units : 20
> OpenCL : Loading kernels
> OpenCL : Loading kernels finished
> OpenCL : Benchmarking
> OpenCL : Initialization completed
> OpenCL benchMark : 0.823120
> OpenCL Device : GeForce GTX 870M
> OpenCL Driver Version : 344.91
> OpenCL Compute Units : 7
> OpenCL : Loading kernels
> OpenCL : Loading kernels finished
> OpenCL : Benchmarking
> OpenCL : Initialization completed
> OpenCL benchMark : 0.319616
> Exiting
> Shutting down
lower benchmark is better (yes, lower!)