Hi,  Utilization is I/O per second to the benchmarked maximum. The maximum value used in the calculation is adjusted for the type and speed of the director. But in newer arrays (Microcode:5773+), the utilization is measured on clock ticks where it actually calculates the count busy and count idle. These are not directly related to I/O's per sec.If there are more Idle tick then its under-utilized and if more busy ticks its over utilized. %busy would account only I/O per second.  Thanks Amita Wasson
I was looking at % Busy metric of FE director and Utilization metric of FE port. The %Busy of FE director is very high sometimes even though the FE port utilization is less, they do not relate each other. (I am using only one port, the other port is empty)  % Busy of FE director shows the percent of time director is busy. Port 0 Utilization is about the calculation of port busy. How is this calculated? Why is the difference in percentages between two? I know that I need to look at the director utilization and keep it under control for better performance, what does actually Utilization of port signify?   Thanks, 
FE %Busy and FE port %Utilization