This is a pretty complicated manner. Seems like processors handle latency different than one another.
Higher latency usually would make most think it would result in lower performance but I have seen one benchmark in particular that showed that latencies 1-5 performed an average value while 6-8, 13 were very poor while the remaining latencies provided much higher points than the rest in nearly every category.
This is something that you will just have to test. Change the value, benchmark, record...etc.
Higher latencies are usually good when high overclocking is being used so that your processor can adjust to the higher frequencies.
Only thing I can tell you is to test test test.