Network streams vs shared variables

Question

I send data from a PXI RT System to users on different Windows computers via Shared Variable and Network Stream.  The user that receives the data via Network Stream writes the data to a disk file (aka DAQ computer).  The users that receive the data via Shared Variable displays it on front panels (aka Observers). 
The data consists of a 1D SGL array where elements 0-3 are the timestamp, element 4 is the counter, and elements 5-1000+ are data.  The timestamp is GPS time and is displayed on all computers.  When I look at the timestamp on the DAQ it is slowly falling behind the current GPS time.  After 4 hours it can be up to a minute behind.  When I look at the timestamp on the Observers it is always displaying current GPS time.  When I look at the code on the PXI System, it is always sending the current GPS time.  The counter on the DAQ computer is also behind.
I am using the Read/Write Single Element Stream functions with the default read/write buffer size of 4096.  The 'timed out?' output is always FALSE for both functions.  No errors are generated.  LabVIEW memory usage is constant during the whole time.
On the PXI RT System the Network Stream and Shared Variable are being written to inside a Timed While Loop.  The users read the data within a standard While Loop.  Everyone is using LabVIEW 2011.
It sounds like a buffer is slowly being filled up somewhere, but where?
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Answer 1

On the PXI RT System:
How often is data sent?
Are you using a “Flush Stream” function after your “Write Single Element to Stream”?
On the “DAQ Computer”:
Are you buffering the reading of the data (i.e. feeding it to a queue)?
You might try using a property node to read “Available Elements for Reading” to see if they are stacking up here.
The buffer size is another option to consider.
steve
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