With that amount of data, I would highly recommend a binary format of some sort, unless you have a very pressing need to save your data in ASCII. LabVIEW gives you several options:
- Use TDMS
- Use NI-HWS
- Use flat binary (you will need to save data lengths)
- Use HDF5
- Use ActiveX to save an actual Excel file
These all have their pluses and minuses depending on what you are planning on doing with your data after you store it. If you can give us more details, we can better suggest a solution.
