Symantec Mail Security for Exchange IOPS REquirements for Exchange 2013

I am planning to deploy Microsoft Exchange Server 2013 using Symantec Mail Security for Exchange as my virus solution. I am using the Exchange 2013 Server Role Requirements Calculator to determine the best server configuration and there is a reference in the calculator for IOPS taking into account the anti-virus solution that I will be using. What I need to know is what does SMSMSE require for additional IOPS in Exchange 2013? I have seen this question asked in this forum but not answered. Does anyone have any info on this?

Thanks in advance.