SANHQ - Current IOPS vs Max Estimated IOPS

Hi - I'm looking at a new 4100E with SANHQ - I'm pretty new to it, so I'm digesting a lot of new stuff right now.

I'm watching the Estimated Max IOPS It's saying 313 right now, but for the last day I'm running between 900 and 1900 IOPS. Read/Write is 58%/42%.

So where is the estimated max coming from? I'm running at least double what the estimated max is right now...