Hey, Stefan, it looks like you are writing the file data the same way I would in VB; you have an array and you loop through the array and write individual elements of the array each time the loop iterates. So each write operation shouldn't be bigger than the array element that is being written. Try modifying your file write code so that every 500 nodes or so (pick your own number here) the write routine closes the file, re-opens it in append mode (so that new data written is added to the end of the file), and then continues writing. That should clear out the write buffer and keep it from being to big without requiring massive re-coding.