TDMS file size limitation?

[Thang Nguyen]

Hi,

I want to now if there is any limitation in the size of the TDMS file? If YES, is there any solution to determine it?

Thank you,

Thang Nguyen

[Herbert]

QUOTE(Thang Nguyen @ May 8 2007, 10:05 AM)

I want to now if there is any limitation in the size of the TDMS file? If YES, is there any solution to determine it?

There is practically no limit to the file size. We can address any piece of data within a signed integer 64 range (that's almost 1000000 TeraBytes). The limiting factor for that would be your harddisc size.

The only limiting factor is that we cash meta data and index information. That means we keep names and properties of all groups and channels in memory, plus everytime you store data to a channel, we will keep a uInt64 value that tells us where in the file that piece of data went. Hence, if you store a large number of objects in a loop with a large number of iterations, you can run out of memory eventually.

To give you an idea of what I mean by large: One of our test cases for TDMS has 10000 channels with dozens of properties and 10000 chunks of raw data each. This test runs just fine on an average office machine. If your requirements are below that, you should be fine. If you ever run into that kind of limits, you might be successful by

• using NI_MinimumBufferSize to reduce the number of times we actually write to disc
  
• changing your group/channel setup to be more efficient
  
• defragmenting your file
  
• using multiple files.
  

Hope that helps,

Herbert