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TDMS File Size Unexpected

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I'm trying to keep track of the TDMS File size as I write it and my options are as follows:


1) Log (Double - Seconds Count) & (Double - Data)

2) Log (Double - Data)


When I log just the data, I just take the 8 Bytes that make up the double and add them to the total count which I keep in a U64 shift register. I am able to accurately cut off the TDMS file and start a new one at a pre-determined size. 


When I log the data + timestamp (seconds double), I am almost high by a factor of 10. 


I assumed the math was the following:


(Data Size) X (# of Channels) X (# of Rows of Data) + (Metadata) = File Size


So if that is true then why attached file so off in size? Windows says its 9M, but when I add up the data it should be around .9M.


(Data Size = 😎 X (2 Channels) X (62436 Rows)  = 0.998976M


Let me know where my logic is flawed.



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Message 1 of 2
Accepted by topic author rkmadse

Try defragmenting the TDMS file after you're done writing.

Message 2 of 2