Turbo mode would allow for increased clock speed conditional on remaining within power consumption and temperature limits, similar to what you probably have on your host CPU (but different, in that the host Turbo mode is meant to boost single thread performance). If you try that on a standard Intel(r) Xeon Phi(tm), you'll likely get a message about non-implementation (so the selection will not take effect).
ECC off is not a recommended mode of operation, although it could give an increase in peak memory bandwidth. You would get no warning of hardware faults which could invalidate your results. One use for the option would be to check whether the performance effect is within ideal limits mentioned in references:
http://en.wikipedia.org/wiki/ECC_memory
