If the signals are one sample, it would take about 10 ns. If the signals are
100Ms, it would depend completelly on your machine.
You'll have to do the benchmarking yourself. Use the profiler, or place the
code in sequence frames, and put a timer before and after it, then subtract
them to find out how long it took. If it executes too fast, put it in a for
loop, and execute it 10000 times or so. Make changes, and spot the
difference.
Or post the code so we can review it.
Regards,
Wiebe.