I'm trying to measure the speed of convolution/correlation in MKL and getting a result which seems to be too low: 0.5 gigaflop.
I'm computing the correlation of a short sequence (n=16) with a long sequence (m=8016) in single precision. I force MKL to use MODE_DIRECT. Using MODE_DIRECT, the op count should be 2*m*n. I do 8000 such correlations and measure the overall time, so time quantization is not an issue.
I seem to be getting the correct answer, so I'm not grossly misusing the function calls.
Does anyone have an idea what the problem could be, or have sample code where they measure speed of convolution/correlations?