Systems Performance Analyzer - Avg Write Resp. Time in MS for SSD Adequate?

Hi:

I'm in the the process of accumulating SPA Disk Group info for all our arrays to ultimately use to determine chargeback costs to customers/users. I've been exporting the info into Excel for further massaging. One area that seems, to some extent, inadequate is the average write response time for SSD/Flash disks. Many of the values are displaying as 'N/A' which I assume means that the value is below 1 ms. But, the kind of analysis that is being performed might end up having invalid information for the SSD's if several of the SSD's were 'almost' a millisecond (e.g. .9) in Avg Write Response Time.

I am assuming, then, that there is no way to get finer granularity for the Avg Write Response Time. Is that correct? Any comments will be appreciated. THX!

Regards,

Paul Pokorski