I'll suggest you use <a
href=" http://www.*-*-*.com/ ;>LabVIEW
VI profiler </a>(Tool->Advanced->Profile VIs...) to analyze your VI.
The information will help determine which of the sub-vis is taken the
most time, etc.

I downloaded your VI to test it, but some of the subVIs were missing
so I couldn't.  However, I would agree with Aderogba that the Profiler
may help you out here more than anything else.  It will give you an
idea of what is drawing your resources.