those alerts you are I getting sound like the "out of the box" enabled Symm IOPS alerts which are global IOPS across whole Symm  I think they are a bit useless so I disable them when I install  there are some other Symm performance alerts which are more useful if you look under alert definitions for Storage Agent for Symm  Anyway to answer your question you could try and reverse engineer the director %util agaist the director IOPS at the same time, however the %util calculation is meant to take into account reads vs writes and hits vs misses.  So this wouldn't be accurate, but I guess its a vague ballpark figure.
The DMX4 is posting alerts of I/O throughput in ECC. The values are 205410kB/s & 397402kB/s. Performance Manager shows a director utilization of max 20% over the week. Therefore how can I determine the max throughput and what is the max throughput value. Is the ECC throughput total over the Dirs (sum or Ave)?
DMX4 posting alerts in ECC of Throughput